CVE-2026-81665

high Red Hat
CVSS v3 Base Score
7.5
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score
0.2%
Exploitation probability in 30 days
Top 89% most likely to be exploited
Attack Characteristics
Attack Vector
Adjacent
Attack Complexity
High
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Published: September 4, 2026 (2 days ago)
Last Modified: September 4, 2026
Vendor: Red Hat
Source: REDHAT

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.

CWE

CWE-122

Affected Products

Red Hat Enterprise Linux 10Red Hat Enterprise Linux 7Red Hat Enterprise Linux 8Red Hat Enterprise Linux 9Red Hat OpenShift Container Platform 4

References

🔗 bugzilla.redhat.com 🔗 www.cve.org 🔗 nvd.nist.gov