{"id":"CVE-2026-63388","aliases":["GHSA-cvq5-vrvr-j338"],"url":"https://o3.security/vulnerability/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.","published":"2026-08-20T17:44:18.435Z","modified":"2026-08-22T03:58:08.426304562Z","cvss":{"score":8.4,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":{"url":"https://github.com/libevent/libevent/commit/52057cb33d0c20c0a0453fbabe6c0c96854931b9","label":"libevent/libevent@52057cb"},"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"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-22T03:58:08.426304562Z"}}