CVE-2026-63381

Name of the Vulnerable Software and Affected Versions Libevent versions prior to 2.1.13 Libevent versions prior to 2.2.2-alpha

Description A use-after-free issue exists in buffer.c when the evbuffer add buffer reference() function processes an output buffer where the out total len variable is zero. The evbuffer free all chains() function frees the initial empty chain without resetting outbuf->first, outbuf->last, or outbuf->last with datap. Consequently, APPEND CHAIN MULTICAST dereferences the dangling chain pointer, which can lead to memory corruption or a process crash.

Recommendations Update to version 2.1.13. Update to version 2.2.2-alpha.