CVE-2026-63380

Libevent: Null Pointer Dereference in `evws_new_session`

State: Published
Severity: 5.7 Medium
Published: Aug 20, 2026
Updated: Aug 25, 2026
Reserved: Jul 16, 2026

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.

Scores

CVSS	Score	Vector	Source
4.0	5.7 Medium	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	GitHub_M

Weaknesses

CWE-416 Use After Free
CWE-476 NULL Pointer Dereference

Affected Products

Product	Versions
libeventlibevent	< 2.2.2-alphaAffected

References

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