{"id":"CVE-2026-76957","title":"libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks","summary":"libexpat 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.","severity":"medium","cvss":4.9,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L","cwe":["CWE-416","CWE-825"],"vendor":"libexpat_project","product":"libexpat","affected":["libexpat < 2.8.4"],"patched":["libexpat 2.8.4"],"published":"2026-08-20","updated":"2026-09-08","sourceUpdated":"2026-09-08T20:56:31.860","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-76957","references":[{"url":"https://github.com/libexpat/libexpat/pull/1322","label":"cve@mitre.org"},{"url":"https://github.com/libexpat/libexpat/pull/1329","label":"cve@mitre.org"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-76957.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-76957"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2520125"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-76957"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-76957"},{"url":"https://access.redhat.com/errata/RHSA-2026:60451"}],"tags":["nvd","csaf","vex","red-hat"],"epss":0.00148,"epssPercentile":0.03323,"ingestedAt":"2026-09-08T21:11:12.284Z","slug":"CVE-2026-76957","body":"## Overview\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.\n\n## Affected\n\n- `libexpat < 2.8.4`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `libexpat 2.8.4`\n\n## Vendor advisories\n\n- **RHSA-2026:60451** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-27 · [advisory](https://access.redhat.com/errata/RHSA-2026:60451)\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-08 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-76957.json)","depth":"sunlit","depthScore":27,"depthScoreParts":{"impact":27,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}