CVE-2026-81665

Name of the Vulnerable Software and Affected Versions Corosync (affected versions not specified)

Description A heap-based buffer overflow exists in the Totem Process Group (totempg) message reassembly of Corosync. The issue occurs during the processing of fragmented multicast messages because the reassembly buffer lacks a runtime bounds check in release builds. A network-adjacent attacker can send specially crafted multicast protocol messages to the cluster to trigger the overflow with controlled data. This can lead to a crash of the Corosync daemon, resulting in a denial of service for the entire cluster, and may potentially allow for further exploitation through heap corruption.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.