Status: UPDATED
| Advisory ID: CVE-2026-81665
Key Details
| CVE | CVE-2026-81665 |
| CVSS Score / Version | 7.5 (High) / CVSS v3.1 |
| Updated | 2026-09-30 |
| CVSS Vector | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CVSS Prose | attack vector is adjacent; attack complexity is high; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high. |
| Affected products | see table below |
| Classified as | CWE-122 (Heap-based Buffer Overflow) |
Affected Products, Subsystems & Sectors
| Subsystems | OT Supporting Infrastructure |
| Sectors | Multiple |
What to Know
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. (NVD)
What to Do
Monitor Red Hat's web page for any future patch releases.
References