CVE-2026-81665 — Corosync: corosync: heap-based buffer overflow in totempg assembly buffer during fragmented message reassembly
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 reassemb…
Published: 2026-09-04 · CVSS: 7.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7