{"id":"CVE-2026-63380","title":"Libevent is an event notification library","summary":"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. ev…","severity":"medium","cwe":["CWE-416","CWE-476"],"published":"2026-08-20","updated":"2026-09-09","sourceUpdated":"2026-09-09T21:19:49.197","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-63380","references":[{"url":"https://github.com/libevent/libevent/commit/825c18bd99f556b59d61200523237f264d5cc734","label":"security-advisories@github.com"},{"url":"https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha","label":"security-advisories@github.com"},{"url":"https://github.com/libevent/libevent/security/advisories/GHSA-3rpf-frgx-xq34","label":"security-advisories@github.com"},{"url":"https://github.com/libevent/libevent/security/advisories/GHSA-3rpf-frgx-xq34","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63380.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-63380"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2520656"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63380"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63380"}],"tags":["nvd","csaf","vex","red-hat"],"epss":0.00113,"epssPercentile":0.01605,"ingestedAt":"2026-09-09T21:22:45.544Z","vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","affected":["enterprise_linux 10","enterprise_linux 6","enterprise_linux 7","enterprise_linux 8","openshift_container_platform 4"],"cvss":4.7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","slug":"CVE-2026-63380","body":"## Overview\n\nLibevent 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63380.json)","depth":"sunlit","depthScore":26,"depthScoreParts":{"impact":25.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":205427,"id":"CVE-2026-63380","ts":1789576707116,"field":"cvss","old":null,"new":"4.7"},{"seq":205426,"id":"CVE-2026-63380","ts":1789576707116,"field":"severity","old":"none","new":"medium"}]}