{"id":"CVE-2026-63388","state":"PUBLISHED","title":"Libevent: Heap out-of-bounds write in bufferevent_socket_set_conn_address_ reachable via AF_UNIX accept","description":"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.","publishedAt":"2026-08-20T17:44:18.435Z","updatedAt":"2026-08-21T21:46:40.675Z","severity":{"score":8.4,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["libevent libevent"],"affected":[{"vendor":"libevent","product":"libevent","versions":[{"version":"< 2.1.13","status":"affected"},{"version":">= 2.2.0-alpha, < 2.2.2-alpha","status":"affected"}]}],"references":["https://github.com/libevent/libevent/security/advisories/GHSA-cvq5-vrvr-j338","https://github.com/libevent/libevent/commit/52057cb33d0c20c0a0453fbabe6c0c96854931b9","https://github.com/libevent/libevent/commit/ef38f926e9cd1f082416c6fff13587bc1f431d72","https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable","https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"],"weaknesses":["CWE-617","CWE-787"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/63xxx/CVE-2026-63388.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63388","state":"PUBLISHED","datePublished":"2026-08-20T17:44:18.435Z","dateUpdated":"2026-08-21T21:46:40.675Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-16T17:39:30.171Z"},"containers":{"cna":{"title":"Libevent: Heap out-of-bounds write in bufferevent_socket_set_conn_address_ reachable via AF_UNIX accept","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"libevent","product":"libevent","versions":[{"version":"< 2.1.13","status":"affected"},{"version":">= 2.2.0-alpha, < 2.2.2-alpha","status":"affected"}]}],"references":[{"url":"https://github.com/libevent/libevent/security/advisories/GHSA-cvq5-vrvr-j338","name":"https://github.com/libevent/libevent/security/advisories/GHSA-cvq5-vrvr-j338","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/libevent/libevent/commit/52057cb33d0c20c0a0453fbabe6c0c96854931b9","name":"https://github.com/libevent/libevent/commit/52057cb33d0c20c0a0453fbabe6c0c96854931b9","tags":["x_refsource_MISC"]},{"url":"https://github.com/libevent/libevent/commit/ef38f926e9cd1f082416c6fff13587bc1f431d72","name":"https://github.com/libevent/libevent/commit/ef38f926e9cd1f082416c6fff13587bc1f431d72","tags":["x_refsource_MISC"]},{"url":"https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable","name":"https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable","tags":["x_refsource_MISC"]},{"url":"https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha","name":"https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":8.4,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-617","lang":"en","description":"CWE-617: Reachable Assertion","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-787","lang":"en","description":"CWE-787: Out-of-bounds Write","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-20T17:44:18.435Z"},"source":{"advisory":"GHSA-cvq5-vrvr-j338","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-21T21:00:24.903079Z","id":"CVE-2026-63388","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-21T21:46:40.675Z"}}]}}}