{"id":"CVE-2026-76957","published":"2026-08-20T04:28:04Z","modified":"2026-08-20T15:26:27Z","title":"libexpat before 2.8.4 lacks handler call depth tracking with custom encoding callbacks","vendor":"libexpat project","product":"libexpat","tier":"tail","description":{"text":"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.","provenance":"source","from":"CVE.org"},"cvss":{"score":4.9,"severity":"MEDIUM","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L","provenance":"source","from":"CVE.org CNA"},"epss":{"score":0.00107,"percentile":0.01115,"provenance":"source"},"cwes":[{"id":"CWE-416","name":"Use After Free"}],"references":[{"url":"https://github.com/libexpat/libexpat/pull/1322","tags":[]},{"url":"https://github.com/libexpat/libexpat/pull/1329","tags":[]}],"priority":{"score":3.7,"factors":[{"name":"EPSS percentile","points":0.22},{"name":"CVSS severity","points":3.43}]},"vendorSlug":"libexpat-project","affectedVersions":[{"vendor":"libexpat project","product":"libexpat","versions":["< 2.8.4"]}],"euvd":{"id":"EUVD-2026-63196","exploited":false,"provenance":"source"},"lineage":{"familyId":"fam-libexpat-cve-2026-50219","parents":[{"from":"CVE-2026-56131","to":"CVE-2026-76957","relation":"related","confidence":"medium","kind":"lineage","evidence":[{"kind":"text","provenance":"source","relation":"related","quote":"NOTE: this is similar to CVE-2026-50219, CVE-2026-56131 and CVE-2026-56412.","from":"CVE.org","in":"CVE-2026-76957"},{"kind":"similar","provenance":"machine","score":0.53,"basis":"same product + CWE + description similarity"}]},{"from":"CVE-2026-56412","to":"CVE-2026-76957","relation":"related","confidence":"medium","kind":"lineage","evidence":[{"kind":"text","provenance":"source","relation":"related","quote":"NOTE: this is similar to CVE-2026-50219, CVE-2026-56131 and CVE-2026-56412.","from":"CVE.org","in":"CVE-2026-76957"},{"kind":"similar","provenance":"machine","score":0.44,"basis":"same product + CWE + description similarity"}]},{"from":"CVE-2026-50219","to":"CVE-2026-76957","relation":"related","confidence":"low","kind":"lineage","evidence":[{"kind":"text","provenance":"source","relation":"related","quote":"NOTE: this is similar to CVE-2026-50219, CVE-2026-56131 and CVE-2026-56412.","from":"CVE.org","in":"CVE-2026-76957"}]}]}}