{"id":"DEBIAN-CVE-2026-81665","details":"A heap-based buffer overflow was found in Corosync's Totem Process Group (totempg) message reassembly. When processing fragmented multicast messages, the buffer used to reassemble fragments lacks a runtime bounds check in release builds. A network-adjacent attacker able to send crafted multicast protocol messages to the cluster could cause a heap buffer overflow with attacker-controlled data. This can crash the Corosync daemon, causing a denial of service to the entire cluster, and may potentially allow further exploitation given sufficient heap-corruption control.","modified":"2026-09-22T08:47:32.152095049Z","published":"2026-09-04T09:17:11.357Z","upstream":["CVE-2026-81665"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-81665"}],"affected":[{"package":{"name":"corosync","ecosystem":"Debian:12","purl":"pkg:deb/debian/corosync?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.10-1","3.1.10-2","3.1.10-3","3.1.10-4","3.1.7-1","3.1.7-1+deb12u1","3.1.7-1+deb12u2","3.1.8-1","3.1.8-2","3.1.8-3","3.1.9-1","3.1.9-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-81665.json"}},{"package":{"name":"corosync","ecosystem":"Debian:13","purl":"pkg:deb/debian/corosync?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.10-1","3.1.10-2","3.1.10-3","3.1.10-4","3.1.9-2","3.1.9-2+deb13u1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-81665.json"}},{"package":{"name":"corosync","ecosystem":"Debian:14","purl":"pkg:deb/debian/corosync?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.10-1","3.1.10-2","3.1.10-3","3.1.10-4","3.1.9-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-81665.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}