CVE-2026-63381
MEDIUM
MEDIUM
Priority: 0.01
BB Relevance:
37/100
Published: 2026-08-20
Modified: 2026-10-26
First seen: 2026-10-29
Status: active
Attack Surface
Low Complexity
No Interaction
CVSS Vector Breakdown
AV:
Local
AC:
Low
PR:
Low
UI:
None
S:
X
AT:
Present
VC:
Low
VI:
Low
VA:
High
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.