Use After Free in Libexpat Project
CVE-2026-56131
libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser from within handlers in cases of a policy violation. Thus, a use-after-free can occur (similar to the CVE-2026-50219 situation).
Vulnerability class: Use-After-Free
CVSS v3 metric
CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.
Affected products
- Libexpat Project — versions 0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-56131?
- CVE-2026-56131 is a medium-severity vulnerability in Libexpat Project, classified under Use After Free. CVSS score: 4.9/10. Published 2026-06-19.
- How severe is CVE-2026-56131?
- Medium severity. CVSS v3 base score is 4.9 out of 10.