VulnerabilityAwaiting Analysis

CVE-2026-81665

A heap-based buffer overflow was found in Corosync's Totem Process Group (totempg) message reassembly.

HIGH 7.5EPSS 0.21%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.21%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 7.5 HIGHCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.21% probability · 12th percentile
CISA KEV: Not listed
Weakness: CWE-122
Source: secalert@redhat.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.