Vulnerability Description
Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a use-after-free in buffer.c when evbuffer_add_buffer_reference processes an output buffer whose out_total_len is zero. evbuffer_free_all_chains frees the initial empty chain without resetting outbuf->first, outbuf->last, or outbuf->last_with_datap, and APPEND_CHAIN_MULTICAST subsequently dereferences the dangling chain pointer. A caller that can drive this buffer state can cause memory corruption or a process crash. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.
Related Weaknesses (CWE)
References
- https://github.com/libevent/libevent/commit/5cb95ba2f804f8aff46f88d58391c71e1251
- https://github.com/libevent/libevent/commit/9db091b04f569be3a700fa9860ef02f90b83
- https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable
- https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha
- https://github.com/libevent/libevent/security/advisories/GHSA-c2pj-cg4r-88c8
FAQ
What is CVE-2026-63381?
CVE-2026-63381 is a documented vulnerability. Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a use-after-free in buffer.c when evbuffer_add_buffer_reference processes an output buffer whose out_total_len ...
How severe is CVE-2026-63381?
CVSS scoring is not yet available for CVE-2026-63381. Check NVD for updates.
Is there a patch for CVE-2026-63381?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.