CVE-2026-63380

medium

Description

Libevent is an event notification library. Prior to 2.2.2-alpha, libevent can dereference invalid list pointers in ws.c when evws_new_session enters its error path after evhttp_start_ws_ succeeds but bufferevent_enable_locking_ fails. evws_connection_free sees a non-null http_server and unconditionally calls TAILQ_REMOVE even though the session was never inserted into http_server->ws_sessions. A local caller able to induce this allocation or locking failure can crash the process. This issue is fixed in version 2.2.2-alpha.

References

https://github.com/libevent/libevent/security/advisories/GHSA-3rpf-frgx-xq34

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

https://github.com/libevent/libevent/commit/825c18bd99f556b59d61200523237f264d5cc734

Details

Source: Mitre, NVD

Published: 2026-08-20

Updated: 2026-08-20

Risk Information

CVSS v2

Base Score: 2.1

Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:P

Severity: Low

CVSS v3

Base Score: 6.2

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: Medium

CVSS v4

Base Score: 5.7

Vector: CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Severity: Medium

EPSS

EPSS: 0.00113