{"id":"CVE-2026-63388","title":"Libevent is an event notification library","summary":"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 buffer…","severity":"high","cvss":8.4,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-617","CWE-787"],"vendor":"libevent","product":"libevent","affected":["libevent < 2.1.13","libevent >= 2.2.0-alpha, < 2.2.2-alpha"],"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-2026-63388","references":[{"url":"https://github.com/libevent/libevent/commit/52057cb33d0c20c0a0453fbabe6c0c96854931b9","label":"security-advisories@github.com"},{"url":"https://github.com/libevent/libevent/commit/ef38f926e9cd1f082416c6fff13587bc1f431d72","label":"security-advisories@github.com"},{"url":"https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable","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-cvq5-vrvr-j338","label":"security-advisories@github.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63388.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-63388"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2520661"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63388"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63388"},{"url":"https://access.redhat.com/errata/RHSA-2026:60853"},{"url":"https://access.redhat.com/errata/RHSA-2026:67909"},{"url":"https://access.redhat.com/errata/RHSA-2026:67908"},{"url":"https://access.redhat.com/errata/RHSA-2026:67910"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-08-21T21:00:24.903079Z"},"ingestedAt":"2026-09-13T16:08:38.505Z","epss":0.00142,"epssPercentile":0.03836,"patched":["hardened_images"],"slug":"CVE-2026-63388","body":"## Overview\n\nLibevent 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:60853** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-29 · [advisory](https://access.redhat.com/errata/RHSA-2026:60853)\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, 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-2026-63388.json)\n- **RHSA-2026:67909** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:67909)\n- **RHSA-2026:67908** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux BaseOS (v. 8) · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:67908)\n- **RHSA-2026:67910** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9) · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:67910)","depth":"twilight","depthScore":46,"depthScoreParts":{"impact":46.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}