An update for xorg-x11-server-xwayland is now available for openEuler-22.03-LTS-SP4 Security Advisory openeuler-security@openeuler.org openEuler security committee openEuler-SA-2026-4480 Final 1.0 1.0 2026-10-22 Initial 2026-10-22 2026-10-22 openEuler SA Tool V1.0 2026-10-22 xorg-x11-server-xwayland security update An update for xorg-x11-server-xwayland is now available for openEuler-22.03-LTS-SP4 Xwayland is an X server for running X clients under Wayland. %package devel Summary: Development package Requires: pkgconfig %description devel The development package provides the developmental files which are necessary for developing Wayland compositors using Xwayland. %prep %autosetup -n xwayland- -p1 %build %meson \ -Ddefault_font_path="catalogue:/etc/X11/fontpath.d,built-ins" \ -Dbuilder_string="Build ID: -" \ -Dxkb_output_dir=/lib/xkb \ -Dxcsecurity=true \ -Dglamor=true \ -Ddri3=true %meson_build Security Fix(es): A flaw was found in the X.Org X server and Xwayland when processing X11 Present extension notifications. Improper error handling during notification creation can leave dangling pointers that lead to a use-after-free condition. This can cause memory corruption or a crash, potentially allowing an attacker to execute arbitrary code or cause a denial of service.(CVE-2025-62229) A flaw was identified in the X.Org X server’s X Keyboard (Xkb) extension where improper bounds checking in the XkbSetCompatMap() function can cause an unsigned short overflow. If an attacker sends specially crafted input data, the value calculation may overflow, leading to memory corruption or a crash.(CVE-2025-62231) A flaw was found in the X.Org X server. This integer underflow vulnerability, specifically in the XKB compatibility map handling, allows an attacker with local or remote X11 server access to trigger a buffer read overrun. This can lead to memory-safety violations and potentially a denial of service (DoS) or other severe impacts.(CVE-2026-33999) A flaw was found in the X.Org X server. This use-after-free vulnerability occurs in the XSYNC fence triggering logic, specifically within the miSyncTriggerFence() function. An attacker with access to the X11 server can exploit this without user interaction, leading to a server crash and potentially enabling memory corruption. This could result in a denial of service or further compromise of the system.(CVE-2026-34001) A flaw was found in the X.Org X server. This vulnerability, an out-of-bounds read, affects the XKB (X Keyboard Extension) modifier map handling. An attacker with access to the X11 server can exploit this by sending a malformed request, which causes the server to read beyond its intended memory boundaries. This can lead to the exposure of sensitive information or cause the server to crash, resulting in a denial of service.(CVE-2026-34002) A flaw was found in the X.Org X server's XKB key types request validation. A local attacker could send a specially crafted request to the X server, leading to an out-of-bounds memory access vulnerability. This could result in the disclosure of sensitive information or cause the server to crash, leading to a Denial of Service (DoS). In certain configurations, higher impact outcomes may be possible.(CVE-2026-34003) ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr(CVE-2026-50257) ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr(CVE-2026-50258) ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr(CVE-2026-50259) ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr(CVE-2026-50260) ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr(CVE-2026-50261) ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr(CVE-2026-50262) ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr(CVE-2026-50263) Local attackers with an X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer overflow via SetFont due to missing glyph boundary checks.(CVE-2026-55999) An update for xorg-x11-server-xwayland is now available for openEuler-22.03-LTS-SP4/openEuler-24.03-LTS/openEuler-24.03-LTS-Next/openEuler-24.03-LTS-SP1/openEuler-24.03-LTS-SP3/openEuler-24.03-LTS-SP4/openEuler-22.03-LTS-SP3/openEuler-24.03-LTS-SP2. openEuler Security has rated this update as having a security impact of critical. A Common Vunlnerability Scoring System(CVSS)base score,which gives a detailed severity rating, is available for each vulnerability from the CVElink(s) in the References section. Critical xorg-x11-server-xwayland https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2025-62229 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2025-62231 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2026-33999 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2026-34001 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2026-34002 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2026-34003 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2026-50257 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2026-50258 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2026-50259 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2026-50260 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2026-50261 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2026-50262 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2026-50263 https://www.openeuler.org/en/security/cve/detail/?cveId=CVE-2026-55999 https://nvd.nist.gov/vuln/detail/CVE-2025-62229 https://nvd.nist.gov/vuln/detail/CVE-2025-62231 https://nvd.nist.gov/vuln/detail/CVE-2026-33999 https://nvd.nist.gov/vuln/detail/CVE-2026-34001 https://nvd.nist.gov/vuln/detail/CVE-2026-34002 https://nvd.nist.gov/vuln/detail/CVE-2026-34003 https://nvd.nist.gov/vuln/detail/CVE-2026-50257 https://nvd.nist.gov/vuln/detail/CVE-2026-50258 https://nvd.nist.gov/vuln/detail/CVE-2026-50259 https://nvd.nist.gov/vuln/detail/CVE-2026-50260 https://nvd.nist.gov/vuln/detail/CVE-2026-50261 https://nvd.nist.gov/vuln/detail/CVE-2026-50262 https://nvd.nist.gov/vuln/detail/CVE-2026-50263 https://nvd.nist.gov/vuln/detail/CVE-2026-55999 openEuler-22.03-LTS-SP4 xorg-x11-server-Xwayland-22.1.2-20.oe2203sp4.aarch64.rpm xorg-x11-server-Xwayland-debuginfo-22.1.2-20.oe2203sp4.aarch64.rpm xorg-x11-server-Xwayland-debugsource-22.1.2-20.oe2203sp4.aarch64.rpm xorg-x11-server-Xwayland-devel-22.1.2-20.oe2203sp4.aarch64.rpm xorg-x11-server-Xwayland-22.1.2-20.oe2203sp4.src.rpm xorg-x11-server-Xwayland-22.1.2-20.oe2203sp4.x86_64.rpm xorg-x11-server-Xwayland-debuginfo-22.1.2-20.oe2203sp4.x86_64.rpm xorg-x11-server-Xwayland-debugsource-22.1.2-20.oe2203sp4.x86_64.rpm xorg-x11-server-Xwayland-devel-22.1.2-20.oe2203sp4.x86_64.rpm A flaw was found in the X.Org X server and Xwayland when processing X11 Present extension notifications. Improper error handling during notification creation can leave dangling pointers that lead to a use-after-free condition. This can cause memory corruption or a crash, potentially allowing an attacker to execute arbitrary code or cause a denial of service. 2026-10-22 CVE-2025-62229 openEuler-22.03-LTS-SP4 High 7.3 AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 A flaw was identified in the X.Org X server’s X Keyboard (Xkb) extension where improper bounds checking in the XkbSetCompatMap() function can cause an unsigned short overflow. If an attacker sends specially crafted input data, the value calculation may overflow, leading to memory corruption or a crash. 2026-10-22 CVE-2025-62231 openEuler-22.03-LTS-SP4 High 7.3 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 A flaw was found in the X.Org X server. This integer underflow vulnerability, specifically in the XKB compatibility map handling, allows an attacker with local or remote X11 server access to trigger a buffer read overrun. This can lead to memory-safety violations and potentially a denial of service (DoS) or other severe impacts. 2026-10-22 CVE-2026-33999 openEuler-22.03-LTS-SP4 High 7.8 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 A flaw was found in the X.Org X server. This use-after-free vulnerability occurs in the XSYNC fence triggering logic, specifically within the miSyncTriggerFence() function. An attacker with access to the X11 server can exploit this without user interaction, leading to a server crash and potentially enabling memory corruption. This could result in a denial of service or further compromise of the system. 2026-10-22 CVE-2026-34001 openEuler-22.03-LTS-SP4 High 7.8 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 A flaw was found in the X.Org X server. This vulnerability, an out-of-bounds read, affects the XKB (X Keyboard Extension) modifier map handling. An attacker with access to the X11 server can exploit this by sending a malformed request, which causes the server to read beyond its intended memory boundaries. This can lead to the exposure of sensitive information or cause the server to crash, resulting in a denial of service. 2026-10-22 CVE-2026-34002 openEuler-22.03-LTS-SP4 Critical 9.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 A flaw was found in the X.Org X server's XKB key types request validation. A local attacker could send a specially crafted request to the X server, leading to an out-of-bounds memory access vulnerability. This could result in the disclosure of sensitive information or cause the server to crash, leading to a Denial of Service (DoS). In certain configurations, higher impact outcomes may be possible. 2026-10-22 CVE-2026-34003 openEuler-22.03-LTS-SP4 High 7.8 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr 2026-10-22 CVE-2026-50257 openEuler-22.03-LTS-SP4 High 7.8 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr 2026-10-22 CVE-2026-50258 openEuler-22.03-LTS-SP4 High 7.8 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr 2026-10-22 CVE-2026-50259 openEuler-22.03-LTS-SP4 High 7.8 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr 2026-10-22 CVE-2026-50260 openEuler-22.03-LTS-SP4 High 7.8 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr 2026-10-22 CVE-2026-50261 openEuler-22.03-LTS-SP4 High 7.8 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr 2026-10-22 CVE-2026-50262 openEuler-22.03-LTS-SP4 Medium 5.5 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 ['Hi all,\n\nCVEs have been issued now, please see inline below\n\nOn Tue, Jun 02, 2026 at 10:01:46AM +1000, Peter Hutterer wrote:', "=======================================================================\nX.Org Security Advisory: June 2, 2026 \n\nIssues in X.Org X server prior to 21.1.23 and Xwayland prior to 24.1.12\n=======================================================================\n\nMultiple issues have been found in the X server and Xwayland implementations\npublished by X.Org for which we are releasing security fixes for in\nxorg-server-21.1.23 and xwayland-24.1.12.\n\nNote that CVEs have been requested for these issues but did not get assigned in\ntime for this disclosure.\n\n* Font Alias Stack-based Buffer Overflow\n\n A mismatch between the X server and the libXfont2 library's maximum\n font name length can cause a stack buffer overflow during font alias\n resolution. The server allocates a 256 byte stack buffer but libXfont2's\n alias target name length is 1024 bytes. A font alias name between 257\n and 1023 bytes causes the X server to copy that name into the undersized\n stack buffer without further checks.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:", 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30136)', 'This issue has been assigned CVE-2026-50256', '* XSYNC Use-After-Free in miSyncDestroyFence()\n\n A client that sets up multiple fence triggers can trigger a\n use-after-free function pointer call. An attacker would connect to the\n X server to set up a fence and await that fence, then a second X\n connection destroys the fence, causing the use-after-free.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30159)', 'This issue has been assigned CVE-2026-50257', '* XKB Key Types Stack-based Buffer Overflow\n\n The X server has multiple stack buffers that are sized\n XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify\n or clamp non-canonical key types to XkbMaxShiftLevel. A client can\n change key types to excessive shift levels and trigger three separate\n stack overflows.\n\n This is caused by an incomplete fix of CVE-2025-26597.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30160)', 'This issue has been assigned CVE-2026-50258', '* XKB SetMap Request Stack-based Buffer Overflow\n\n _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256]\n indexed by key type index. The helper function CheckKeyTypes() writes\n to this buffer at a client-controlled offset, allowing a stack buffer\n overflow.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30161)', 'This issue has been assigned CVE-2026-50259', '* XSYNC Use-After-Free in FreeCounter()\n\n A client that sets up multiple SyncCounters and awaits on those\n triggers can trigger a use-after-free when destroying those counters\n via a second client connection.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30163)', 'This issue has been assigned CVE-2026-50260', '* XSYNC Use-After-Free in SyncChangeCounter()\n\n A client that sets up multiple SyncCounters can trigger a use-after-free\n when destroying those counters via a second client connection while\n changing those counters.\n\n Fixed in: xorg-server-21.1.23 and xwayland-24.1.12\n Fix:', 'Found by: Anonymous working with TrendAI Zero Day Initiative.\n (ZDI-CAN-30164)', 'This issue has been assigned CVE-2026-50261', '* GLX ChangeDrawableAttributes Out-Of-Bounds Read/Write\n\n A wrong size validation check in __glXDisp_ChangeDrawableAttributes()\n can read (or write) a client-contr 2026-10-22 CVE-2026-50263 openEuler-22.03-LTS-SP4 Medium 5.5 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480 Local attackers with an X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer overflow via SetFont due to missing glyph boundary checks. 2026-10-22 CVE-2026-55999 openEuler-22.03-LTS-SP4 High 8.5 AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H xorg-x11-server-xwayland security update 2026-10-22 https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4480