CVE-2026-63388
Published: August 22, 2026Last modified: September 1, 2026
Description
Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a heap out-of-bounds write in bufferevent_sock.c when bufferevent_socket_set_conn_address_ copies a kernel-supplied AF_UNIX peer address into bufferevent_private.conn_address. Release builds compiled with NDEBUG disable the EVUTIL_ASSERT length guard, and the evhttp accept path can pass a 110-byte sockaddr from accept() into the 28-byte field. An unauthenticated local peer able to connect to an AF_UNIX listener can overwrite the adjacent dns_request pointer and heap data, causing memory corruption with confidentiality, integrity, and availability impact. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 8.4 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | libevent | Fixed (2.1.13-r0) |
| 25 LTS | libevent | Fixed (2.1.13-r0) | |
| Stream | libevent | Fixed (2.1.13-r0) | |
| Hardened Containers | 23 LTS | libevent | Fixed (2.1.13-r0) |
| 25 LTS | libevent | Fixed (2.1.13-r0) | |
| Stream | libevent | Fixed (2.1.13-r0) |
References
- https://github.com/libevent/libevent/commit/52057cb33d0c20c0a0453fbabe6c0c96854931b9
- https://github.com/libevent/libevent/commit/ef38f926e9cd1f082416c6fff13587bc1f431d72
- 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-cvq5-vrvr-j338