CVE-2026-81666
Fixed in a distro release EPSS <1%CVSS 6.5
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.
Products: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Debian 12 | corosync | no fix |
| Debian 13 | corosync | no fix |
| Debian 14 | corosync | no fix |
| SUSE Linux Enterprise High Availability Extension 15 SP4 | corosync | 2.4.6-150300.12.19.1 |
| SUSE Linux Enterprise High Availability Extension 15 SP5 | corosync | 2.4.6-150300.12.19.1 |
| SUSE Linux Enterprise High Availability Extension 15 SP6 | corosync | 2.4.6-150300.12.19.1 |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | corosync | 2.4.6-150300.12.19.1 |
| SUSE Linux Enterprise High Availability Extension 16.0 | corosync | 3.1.9-160000.4.1 |
| Ubuntu 16.04 LTS | corosync | no fix |
| Ubuntu 18.04 LTS | corosync | no fix |
| Ubuntu 20.04 LTS | corosync | no fix |
| Ubuntu 22.04 LTS | corosync | no fix |
| Ubuntu 24.04 LTS | corosync | no fix |
| Ubuntu 26.04 LTS | corosync | no fix |
| Ubuntu 26.10 | corosync | no fix |
| openSUSE Leap 16.0 | corosync | 3.1.9-160000.4.1 |
| openSUSE Tumbleweed | corosync | 3.1.10-5.1 |