{"id":"CVE-2026-81666","title":"An integer overflow was found in Corosync's handling of membership commit token messages","summary":"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 mess…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-190"],"vendor":"Red Hat","product":"corosync","affected":["corosync (all versions)","corosync (all versions)","corosync (all versions)","corosync (all versions)","rhcos (all versions)"],"published":"2026-09-04","updated":"2026-09-08","sourceUpdated":"2026-09-08T19:08:15.590","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-81666","references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-81666","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2524923","label":"secalert@redhat.com"}],"tags":["nvd","cve.org"],"epss":0.00271,"epssPercentile":0.19547,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-08T14:41:30.256254Z"},"ingestedAt":"2026-09-08T15:33:26.960Z","slug":"CVE-2026-81666","body":"## Overview\n\nAn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}