CVE-2026-81666

Public on 2026-09-04
Modified on 2026-09-05
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.
Severity
Medium severity
Medium
See what this means
CVSS v3 Base Score
6.5
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Core corosync Not Affected
Amazon Linux 2023 corosync Not Affected
Amazon Linux 2027 Preview corosync Not Affected

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H