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OpenAdvisories
Medium · 6.5 CVE-2026-81666 EUVD-2026-70987GHSA-8297-6g53-8gp5

Corosync: corosync: integer overflow in check_memb_commit_token_sanity may bypass message length validation on 32-bit systems

Published Sep 4, 2026 · Updated Nov 6, 2026 · Assigned by redhat

Description

An integer overflow was found in Corosync's handling of membership commit token messages. The length-validation check for these messages can be bypassed on 32-bit systems due to an integer overflow in the calculation of the expected message length, allowing a crafted network packet to trigger an out-of-bounds memory access that crashes the Corosync daemon. This results in a denial of service for the affected cluster node. The overflow does not occur on 64-bit systems, where the length calculation is correctly performed in 64-bit arithmetic.

Affected products

VendorProductAffectedFixed
Red Hat Red Hat Enterprise Linux 10 — —
Red Hat Red Hat Enterprise Linux 7 — —
Red Hat Red Hat Enterprise Linux 8 — —
Red Hat Red Hat Enterprise Linux 9 — —
Red Hat Red Hat OpenShift Container Platform 4 — —
Red Hat Red Hat OpenShift Container Platform 5 — —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 corosync No fix yet —
Debian 13 corosync No fix yet —
Debian 12 corosync No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 corosync No fix yet —
Ubuntu 26.04 LTS corosync No fix yet —
Ubuntu 24.04 LTS corosync No fix yet —
Ubuntu 22.04 LTS corosync No fix yet —
Ubuntu 20.04 LTS corosync No fix yet —
Show 2 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 18.04 LTS corosync No fix yet —
Ubuntu 16.04 LTS corosync No fix yet —
ReleasePackageFixed inAdvisory
SLES 15 SP7 corosync 2.4.6-150300.12.19.1 SUSE-SU-2026:4202-1
SLES 15 SP6 corosync 2.4.6-150300.12.19.1 SUSE-SU-2026:4202-1
SLES 15 SP5 corosync 2.4.6-150300.12.19.1 SUSE-SU-2026:4202-1
SLES 15 SP4 corosync 2.4.6-150300.12.19.1 SUSE-SU-2026:4202-1
Show 1 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES 16.0 corosync 3.1.9-160000.4.1 SUSE-SU-2026:23850-1
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed corosync 3.1.10-5.1 openSUSE-SU-2026:11715-1
openSUSE Leap 16.0 corosync 3.1.9-160000.4.1 openSUSE-SU-2026:21887-1

Advisories 4

References