VULNERABILITY INTELLIGENCE
CVE-2026-81665
CVSS score7.5 HIGH
EPSS probability0.42%
CISA KEVNot currently listed
Published2026-09-04
Last modified2026-10-21
CVSS vectorCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Description
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.
Weakness classification
- secalert@redhat.com: CWE-122