# CVE-2026-81666

## Summary

- **CVE ID:** CVE-2026-81666
- **Severity:** MEDIUM
- **CVSS Score:** 6.5 (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** CWE-190
- **Published:** Sep 4, 2026
- **Last Modified:** Sep 8, 2026

## 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

No affected products listed.

## References

- [CNA](https://access.redhat.com/security/cve/CVE-2026-81666)
- [CNA](https://bugzilla.redhat.com/show_bug.cgi?id=2524923)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.27%
- **EPSS Percentile:** 19.2

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._