CVE-2026-63380
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.
What this means for your business
- FIRST's prediction model gives it a 0.1% chance of attack attempts being seen in the next 30 days, ranking above 2% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
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Scoring
- CVSS
- Not yet scored
- CVSS v4
- 5.7
- Weakness
- CWE-416
- Assigned by
- security-advisories@github.com
Dates
- Published
- 2026-08-20
- Last modified
- 2026-09-09
- Sources
- NVD
References
- https://github.com/libevent/libevent/commit/825c18bd99f556b59d61200523237f264d5cc734
- https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha
- https://github.com/libevent/libevent/security/advisories/GHSA-3rpf-frgx-xq34
- https://github.com/libevent/libevent/security/advisories/GHSA-3rpf-frgx-xq34