{"id":"CVE-2026-63388","summary":"Libevent: Heap out-of-bounds write in bufferevent_socket_set_conn_address_ reachable via AF_UNIX accept","details":"Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has a heap out-of-bounds write in bufferevent_sock.c when bufferevent_socket_set_conn_address_ copies a kernel-supplied AF_UNIX peer address into bufferevent_private.conn_address. Release builds compiled with NDEBUG disable the EVUTIL_ASSERT length guard, and the evhttp accept path can pass a 110-byte sockaddr from accept() into the 28-byte field. An unauthenticated local peer able to connect to an AF_UNIX listener can overwrite the adjacent dns_request pointer and heap data, causing memory corruption with confidentiality, integrity, and availability impact. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.","aliases":["GHSA-cvq5-vrvr-j338"],"modified":"2026-08-23T03:49:31.652444733Z","published":"2026-08-20T17:44:18.435Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-617","CWE-787"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63388.json"},"references":[{"type":"WEB","url":"https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"},{"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-2026-63388.json"},{"type":"ADVISORY","url":"https://github.com/libevent/libevent/security/advisories/GHSA-cvq5-vrvr-j338"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63388"},{"type":"FIX","url":"https://github.com/libevent/libevent/commit/52057cb33d0c20c0a0453fbabe6c0c96854931b9"},{"type":"FIX","url":"https://github.com/libevent/libevent/commit/ef38f926e9cd1f082416c6fff13587bc1f431d72"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/libevent/libevent","events":[{"introduced":"0"},{"fixed":"79ddfb460847999b807cba76d04e73891f29c6ee"},{"fixed":"df3ecad3a040fd6d4fad4287defe113395de6fd7"},{"fixed":"52057cb33d0c20c0a0453fbabe6c0c96854931b9"},{"fixed":"ef38f926e9cd1f082416c6fff13587bc1f431d72"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"2.1.13"},{"introduced":"2.2.0-alpha"},{"fixed":"2.2.2-alpha"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["release-2.1.12-stable","release-2.2.1-alpha","release-2.1.11-stable","release-2.1.10-stable","release-2.1.9-beta","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":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63388.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}