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.

Medium CVSS 4.9

CVECVE-2026-76957

First seen2026-08-20 08:30 UTC

Disclosed2026-08-20 05:16 UTC

Last updated2026-08-20 08:30 UTC

Channel statusauto

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.

In-depth triage

No in-depth report has been generated yet (DR-003 v2 AI pipeline is under construction).

Sources

NVD DATABASE

Original Links

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

Timeline

2026-08-20 nvd_ingest NVD