{"id":"UBUNTU-CVE-2026-50161","details":"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 frame that uses the 64-bit extended length encoding. The expression 4 + hdr-\u003elen can wrap when hdr-\u003elen 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.","modified":"2026-10-17T12:58:32.553307733Z","published":"2026-08-18T18:17:00Z","upstream":["CVE-2026-50161"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-50161"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-50161"},{"type":"REPORT","url":"https://github.com/baresip/re/security/advisories/GHSA-hvxv-v2gp-v93h"},{"type":"REPORT","url":"https://github.com/baresip/re/pull/1584"}],"affected":[{"package":{"name":"libre","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/libre?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.4.14-1","0.4.14-2","0.4.14-3","0.4.14-4"],"ecosystem_specific":{"binaries":[{"binary_name":"libre0","binary_version":"0.4.14-4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50161.json"}},{"package":{"name":"libre","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/libre?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.5.4-3ubuntu1","0.5.5-1ubuntu1","0.5.6-1ubuntu1","0.5.6-1ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_version":"0.5.6-1ubuntu2","binary_name":"libre0"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50161.json"}},{"package":{"name":"libre","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libre?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.6.0-4"],"ecosystem_specific":{"binaries":[{"binary_name":"libre0","binary_version":"0.6.0-4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50161.json"}},{"package":{"name":"libre","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libre?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.0-1","1.1.0-1build1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.1.0-1build1","binary_name":"libre0"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50161.json"}},{"package":{"name":"libre","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libre?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.0-1build2","1.1.0-1build3","1.1.0-1build4"],"ecosystem_specific":{"binaries":[{"binary_version":"1.1.0-1build4","binary_name":"libre0"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50161.json"}},{"package":{"name":"libre","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/libre?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.1-3build1","2.0.1-3ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_name":"libre1","binary_version":"2.0.1-3ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50161.json"}},{"package":{"name":"libre","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libre?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.1-3","2.0.1-3build1"],"ecosystem_specific":{"binaries":[{"binary_name":"libre1","binary_version":"2.0.1-3build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50161.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"},{"type":"Ubuntu","score":"medium"}]}