{"schema_version":"1.7.2","id":"OESA-2026-3671","modified":"2026-09-05T15:03:46Z","published":"2026-09-05T15:03:46Z","upstream":["CVE-2026-66046","CVE-2026-76641","CVE-2026-76957"],"summary":"expat security update","details":"expat is a stream-oriented XML parser library written in C. expat excels with files too large to fit RAM, and where performance and flexibility are crucial.\r\n\r\nSecurity Fix(es):\n\nExpat through 2.8.3 contains a denial of service vulnerability caused by quadratic algorithmic complexity in the storeAtts() function in xmlparse.c, where processing N specified attributes with non-normalized values triggers an O(N^2) linear scan of elementType->defaultAtts to determine CDATA status. A remote unauthenticated attacker can supply a single well-formed XML document of a few megabytes to an application parsing untrusted XML to cause excessive CPU consumption, resulting in denial of service without requiring authentication, external entity resolution, or non-default parser options.(CVE-2026-66046)\n\nExpat through 2.8.3 contains an out-of-bounds read vulnerability that allows attackers to trigger memory corruption by processing XML with external entity parsers created via XML_ExternalEntityParserCreate. A struct size mismatch between ELEMENT_TYPE members causes storeAtts to read the attIndex member past allocated memory boundaries, resulting in failure to normalize whitespace in non-CDATA attributes or a wild pointer dereference causing a segfault. This vulnerability was introduced by the fix for CVE-2026-66046.(CVE-2026-76641)\n\nlibexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks. Thus, a use-after-free can occur. NOTE: this is similar to CVE-2026-50219, CVE-2026-56131 and CVE-2026-56412.(CVE-2026-76957)","affected":[{"package":{"ecosystem":"openEuler:24.03-LTS-SP1","name":"expat","purl":"pkg:rpm/openEuler/expat&distro=openEuler-24.03-LTS-SP1"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.5.0-27.oe2403sp1"}]}],"ecosystem_specific":{"aarch64":["expat-2.5.0-27.oe2403sp1.aarch64.rpm","expat-debuginfo-2.5.0-27.oe2403sp1.aarch64.rpm","expat-debugsource-2.5.0-27.oe2403sp1.aarch64.rpm","expat-devel-2.5.0-27.oe2403sp1.aarch64.rpm"],"noarch":["expat-help-2.5.0-27.oe2403sp1.noarch.rpm"],"src":["expat-2.5.0-27.oe2403sp1.src.rpm"],"x86_64":["expat-2.5.0-27.oe2403sp1.x86_64.rpm","expat-debuginfo-2.5.0-27.oe2403sp1.x86_64.rpm","expat-debugsource-2.5.0-27.oe2403sp1.x86_64.rpm","expat-devel-2.5.0-27.oe2403sp1.x86_64.rpm"]}}],"references":[{"type":"ADVISORY","url":"https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-3671"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66046"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-76641"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-76957"}],"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}],"database_specific":{"severity":"High"}}