CVE-2026-76957: Libexpat Project Libexpat

High severity, CVSS 7.8. EPSS: 0.1% chance of exploitation in the next 30 days.

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.

Affected products

• Libexpat Project Libexpat: before 2.8.4 (fixed in 2.8.4)

Published 2026-08-20. Last modified 2026-09-08.