CVE-2026-76957

Published: 8/20/2026 Last updated: 8/20/2026 Reserved: 8/20/2026

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.

CNA assigner: mitre (8254265b-2729-46b6-b9e3-3dfca2d5bfca) Requested by: n/a

Metrics

Version	Score	Severity	Vector String
3.1	4.9	Medium	CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

Opam packages affected (4)

conf-expat conf-gtk2 conf-gtk3 ocaml-expat

Products affected (0)

No product listed.

References (2)

https://github.com/libexpat/libexpat/pull/1322
https://github.com/libexpat/libexpat/pull/1329