{"id":"CVE-2026-63380","summary":"Libevent: Null Pointer Dereference in `evws_new_session`","details":"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-\u003ews_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.","aliases":["GHSA-3rpf-frgx-xq34"],"modified":"2026-09-11T08:36:40.269484Z","published":"2026-08-20T17:52:29.458Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-416","CWE-476"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63380.json"},"references":[{"type":"WEB","url":"https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63380.json"},{"type":"ADVISORY","url":"https://github.com/libevent/libevent/security/advisories/GHSA-3rpf-frgx-xq34"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63380"},{"type":"FIX","url":"https://github.com/libevent/libevent/commit/825c18bd99f556b59d61200523237f264d5cc734"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/libevent/libevent","events":[{"introduced":"0"},{"fixed":"825c18bd99f556b59d61200523237f264d5cc734"},{"fixed":"df3ecad3a040fd6d4fad4287defe113395de6fd7"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"2.2.2-alpha"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["release-2.2.1-alpha","release-2.1.8-stable","release-2.1.7-rc","release-2.1.6-beta","release-2.1.5-beta","release-2.1.4-alpha","release-2.1.3-alpha","release-2.1.2-alpha","release-2.1.1-alpha","release-2.0.10-stable","release-2.0.9-rc","release-2.0.8-rc","release-2.0.7-rc","release-2.0.6-rc","release-2.0.5-beta","release-2.0.4-alpha","release-2.0.3-alpha","release-2.0.1-alpha","release-1.1b"],"database_specific":{"vanir_signatures":[{"deprecated":false,"digest":{"function_hash":"159443554126248192493229143747497657830","length":554},"id":"CVE-2026-63380-09212634","signature_type":"Function","signature_version":"v1","source":"https://github.com/libevent/libevent/commit/df3ecad3a040fd6d4fad4287defe113395de6fd7","target":{"file":"test/regress_http.c","function":"http_check_transfer_encoding_test"}},{"signature_version":"v1","source":"https://github.com/libevent/libevent/commit/825c18bd99f556b59d61200523237f264d5cc734","target":{"file":"ws.c","function":"evws_new_session"},"deprecated":false,"digest":{"function_hash":"109130475099308657912088269231344217540","length":1567},"id":"CVE-2026-63380-32f30039","signature_type":"Function"},{"target":{"file":"test/regress_ws.h"},"deprecated":false,"digest":{"line_hashes":["12647982394466731349831889809799030260","264215241224195077287317322601949316099"],"threshold":0.9},"id":"CVE-2026-63380-59466181","signature_type":"Line","signature_version":"v1","source":"https://github.com/libevent/libevent/commit/825c18bd99f556b59d61200523237f264d5cc734"},{"source":"https://github.com/libevent/libevent/commit/825c18bd99f556b59d61200523237f264d5cc734","target":{"file":"test/regress_http.c"},"deprecated":false,"digest":{"line_hashes":["300040686730975273327299315686611542202","72844154954073757291137735778070323097","178548446649851378935652704531537255424","23263350071766109139076559634558302065"],"threshold":0.9},"id":"CVE-2026-63380-5bc19ba2","signature_type":"Line","signature_version":"v1"},{"deprecated":false,"digest":{"line_hashes":["272107415239725668246268393803127272733","297144625250709748572882526440735708368","120513486491616251756685362566043001498","88450410138200125229241257115631843456","96261164153256388220643619404943974388","22378475227500572697210277838568698009","211898433567058404227207926514924540074","192659641472638062136153095361932349719","216797439222208293173200562309594500665","63734940667610721703815773521347641421","107730368953637208715596332353445266769","304719011828187362210538232408447785234","124728828777903179019537891110621298691","183936998241613277345926182088185582974","293488546703824324203065045966763482528","5139447175178161093560214447119408933","71397829331915352148422062382668744494","154849801780134921130279735104535517177","64370767142523821929392944315537616661"],"threshold":0.9},"id":"CVE-2026-63380-6adb9b92","signature_type":"Line","signature_version":"v1","source":"https://github.com/libevent/libevent/commit/825c18bd99f556b59d61200523237f264d5cc734","target":{"file":"ws.c"}},{"id":"CVE-2026-63380-923050c6","signature_type":"Line","signature_version":"v1","source":"https://github.com/libevent/libevent/commit/df3ecad3a040fd6d4fad4287defe113395de6fd7","target":{"file":"test/regress_http.c"},"deprecated":false,"digest":{"line_hashes":["270762094980121927552802584929566056086","37564212311334647331345684303177453724","168570413533780985513641597969239978857"],"threshold":0.9}}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63380.json","vanir_signatures_modified":"2026-09-11T08:36:40Z"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}