Cluster-node crash via membership-token length overflow
Published Sep 4, 2026 · Updated Sep 4, 2026
Integer overflow in Corosync on 32-bit Red Hat platforms allows remote attackers to crash a cluster node with a crafted packet. check_memb_commit_token_sanity calculates the expected membership-token length with overflowing 32-bit arithmetic, letting a short packet pass validation and cause an out-of-bounds access. Exploitation requires adjacent access to Corosync UDP ports on a 32-bit node, with message authentication disabled; 64-bit builds are unaffected.
Summary
What happened
Integer overflow in Corosync on 32-bit Red Hat platforms allows remote attackers to crash a cluster node with a crafted packet. check_memb_commit_token_sanity calculates the expected membership-token length with overflowing 32-bit arithmetic, letting a short packet pass validation and cause an out-of-bounds access. Exploitation requires adjacent access to Corosync UDP ports on a 32-bit node, with message authentication disabled; 64-bit builds are unaffected.
The record
- CVE
- CVE-2026-81666
- Published
- Sep 4, 2026
- Updated
- Sep 4, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat Enterprise Linux 10
- Classifications
- CWE-190, T1499
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 4, 2026CVE publishedPublication date reported by the CVE source.
- Sep 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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