CVE-2026-63381

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.

References

https://github.com/libevent/libevent/security/advisories/GHSA-c2pj-cg4r-88c8

https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha

https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable

https://github.com/libevent/libevent/commit/9db091b04f569be3a700fa9860ef02f90b830af9

https://github.com/libevent/libevent/commit/5cb95ba2f804f8aff46f88d58391c71e1251cd1c

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4

EPSS