{"id":"CVE-2026-50161","title":"libre is a generic library for real-time communications with asynchronous input and output support","summary":"libre is a generic library for real-time communications with asynchronous input and output support. Prior to 4.8.1, the websock_decode() function in src/websock/websock.c contains an integer overflow when validating a masked WebSocket fr…","severity":"critical","cwe":["CWE-190","CWE-787"],"published":"2026-08-18","updated":"2026-09-18","sourceUpdated":"2026-09-18T20:09:01.757","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-50161","references":[{"url":"https://github.com/baresip/re/commit/718b92615c7963670d26c1a2b246968b58d782e8","label":"security-advisories@github.com"},{"url":"https://github.com/baresip/re/pull/1584","label":"security-advisories@github.com"},{"url":"https://github.com/baresip/re/releases/tag/v4.8.1","label":"security-advisories@github.com"},{"url":"https://github.com/baresip/re/security/advisories/GHSA-hvxv-v2gp-v93h","label":"security-advisories@github.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-50161.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-50161"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-50161"}],"tags":["nvd","csaf","vex","red-hat"],"epss":0.00384,"epssPercentile":0.32339,"ingestedAt":"2026-09-18T20:51:25.633Z","vendor":"Red Hat","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"vendor","slug":"CVE-2026-50161","body":"## Overview\n\nlibre is a generic library for real-time communications with asynchronous input and output support. Prior to 4.8.1, the websock_decode() function in src/websock/websock.c contains an integer overflow when validating a masked WebSocket frame that uses the 64-bit extended length encoding. The expression 4 + hdr->len can wrap when hdr->len is close to UINT64_MAX, causing the mbuf_get_left() bounds check to pass. The subsequent XOR unmasking loop then writes beyond the heap buffer. Applications using websock_accept() or websock_accept_proto() to implement a WebSocket server are affected, and exploitation can cause attacker-controlled heap corruption or denial of service after the HTTP WebSocket upgrade handshake. This issue is fixed in version 4.8.1.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · updated 2026-09-22 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-50161.json)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":209509,"id":"CVE-2026-50161","ts":1790149098195,"field":"cvss","old":null,"new":"9.8"},{"seq":209508,"id":"CVE-2026-50161","ts":1790149098195,"field":"severity","old":"none","new":"critical"}]}