CVE-2026-63381
CVE-2026-63381
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.
Published · last modified .
EPSS exploit prediction
EPSS: 0.002 (4.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 4.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000
Weakness classification (CWE)
References
- github.com/libevent/libevent/security/advisories/GHSA-c2pj-cg4r-88c8
- github.com/libevent/libevent/commit/5cb95ba2f804f8aff46f88d58391c71e1251cd1c
- github.com/libevent/libevent/commit/9db091b04f569be3a700fa9860ef02f90b830af9
- github.com/libevent/libevent/releases/tag/release-2.1.13-stable
- github.com/libevent/libevent/releases/tag/release-2.2.2-alpha