{"cve":"CVE-2026-63388","nvd":{"published":"2026-08-20T18:16:36.893","modified":"2026-10-26T10:10:00.140","status":"Awaiting Analysis","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.4},"cwes":["CWE-617","CWE-787"],"references":["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","https://github.com/libevent/libevent/security/advisories/GHSA-cvq5-vrvr-j338"],"products":[],"source":"nvd","synced_at":"2026-10-26T10:28:23.151169805+00:00"},"epss":{"cve":"CVE-2026-63388","score":0.00142,"percentile":0.0345,"date":"2026-10-26"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}