Heap-based Buffer Overflow Affecting corosynclib package, versions <0:3.1.10-1.el10_2.2


Severity

Recommended
0.0
high
0
10

Based on AlmaLinux security rating.

Threat Intelligence

EPSS
0.35% (26th percentile)

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  • Snyk IDSNYK-ALMALINUX10-COROSYNCLIB-20360371
  • published1 Oct 2026
  • disclosed16 Sept 2026

Introduced: 16 Sep 2026

CVE-2026-81665  (opens in a new tab)
CWE-122  (opens in a new tab)

How to fix?

Upgrade AlmaLinux:10 corosynclib to version 0:3.1.10-1.el10_2.2 or higher.
This issue was patched in ALSA-2026:67872.

NVD Description

Note: Versions mentioned in the description apply only to the upstream corosynclib package and not the corosynclib package as distributed by AlmaLinux. See How to fix? for AlmaLinux:10 relevant fixed versions and status.

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 Base Scores

version 3.1