Medium
corosync — security advisory
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
- corosync
- Affected versions
- 2.3.4-0ubuntu1, 2.3.5-3, 2.3.5-3ubuntu1, 2.3.5-3ubuntu2, 2.3.5-3ubuntu2.1, 2.3.5-3ubuntu2.3, 2.4.2-3build1, 2.4.2-3ubuntu1, 2.4.3-0ubuntu1, 2.4.3-0ubuntu1.1, 2.4.3-0ubuntu1.2, 2.4.3-0ubuntu1.3, 3.0.1-2ubuntu1, 3.0.2-1ubuntu1, 3.0.2-1ubuntu2, 3.0.3-2ubuntu1, 3.0.3-2ubuntu2, 3.0.3-2ubuntu2.1, 3.0.3-2ubuntu2.2, 3.1.10-2ubuntu2, 3.1.10-3ubuntu1, 3.1.2-2ubuntu1, 3.1.6-1ubuntu1, 3.1.6-1ubuntu1.1, 3.1.6-1ubuntu1.2, 3.1.7-1ubuntu1, 3.1.7-1ubuntu2, 3.1.7-1ubuntu3, 3.1.7-1ubuntu3.1, 3.1.7-1ubuntu3.2, 3.1.9-2ubuntu1, 3.1.9-2ubuntu2, 3.1.9-2ubuntu3
- Fixed versions
- Not specified
- CVEs
- CVE-2026-81666
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:20 UTC · Revision 1
Source evidence
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.
osv:UBUNTU-CVE-2026-81666
corosync
Fixed versions: Not specified
corosync
Fixed versions: Not specified
corosync
Fixed versions: Not specified
corosync
Fixed versions: Not specified
corosync
Fixed versions: Not specified
corosync
Fixed versions: Not specified
corosync
Fixed versions: Not specified
Complete source record
{
"id": "b2247b8fe884218a921ba83a677d09d7e5b6003b01fa6c85cb4084a0b0cea865",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-81666",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-81666",
"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 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.",
"evidence": "osv:UBUNTU-CVE-2026-81666",
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"aliases": [
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],
"modified": "2026-10-17T13:01:11.370636580Z",
"provider": "osv",
"upstream": [
"CVE-2026-81666"
],
"references": [
"https://ubuntu.com/security/CVE-2026-81666",
"https://www.cve.org/CVERecord?id=CVE-2026-81666"
]
},
"related_cves": [
{
"value": "CVE-2026-81666",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 361182,
"published_at": "2026-09-04T10:17:00+00:00"
}