Security fix · CVE-2026-81666
An integer overflow was found in Corosync's handling of membership commit token messages.
Published Sep 4, 2026 · catalog updated Oct 21, 2026 · An integer overflow was
Last checked Oct 25, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2026-81666. EPSS is 0.25%. Act only if a listed version of An integer overflow was is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (An integer overflow was).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Medium6.5
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.25%
- Remediation
- Advisory link
- Affected products
- See sources for product scope
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.
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix CVE-2026-81666
No stored fix
No vendor fix text is stored. Use the linked advisory before you change production.
Version check
No version range is stored, so an installed version cannot be checked on this page.
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-81666. EPSS is 0.25%. Act only if a listed version of An integer overflow was is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-190: Integer Overflow. EPSS 0.25%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Sep 4, 2026 · NIST NVD
Detected
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 t
Oct 21, 2026 · NIST NVD
Updated
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 t
Oct 21, 2026 · NIST NVD
Updated
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 t
Sources
- CVE.orgVulnerability recordCVE-2026-81666
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-81666
30-day exploitation probability 0.25%
first.org - NIST NVDVulnerability recordCVE-2026-81666
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 pack
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 25, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- FIRST EPSSOct 25, 2026
- CVE.orgOct 22, 2026
- NIST NVDOct 22, 2026