An integer overflow was found in Corosync's handling of membership commit token messages. (CVE-2026-81666)

CVE-2026-81666 describes an integer overflow in Corosync's processing of membership commit token messages on 32-bit architectures. The vulnerability arises because the length-validation check can be bypassed due to an integer overflow during the expected message length calculation. This flaw enables crafted network packets to trigger out-of-bounds memory access, crashing the Corosync daemon and resulting in denial of service. The vulnerability is specific to 32-bit systems; 64-bit systems are not affected as they perform length calculations using 64-bit arithmetic.

Exploitation of this vulnerability causes a denial of service by crashing the Corosync daemon on affected 32-bit cluster nodes. There is no impact on confidentiality or integrity, and 64-bit systems are not vulnerable.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch is available, affected users on 32-bit systems should consider mitigating exposure by restricting network access to Corosync or using alternative cluster management solutions. No action is required on 64-bit systems as they are not affected.