Open Cluster Management (OCM): Cross-cluster privilege escalation via improper Kubernetes client certificate renewal validation
A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM). Improper validation of Kubernetes client certificate renewal allows a managed cluster administrator to forge a client certificate that can be approved by the OCM controller. This enables cross-cluster privilege escalation and may allow an attacker to gain control over other managed clusters, including the hub cluster.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-4740US | — | — | ||
A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM). Improper validation of Kubernetes client certificate renewal… | ||||
references
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/CVE-2026-4740WEB
- https://blog.arfevrier.fr/open-cluster-management-cross-cluster-escapeWEB
- https://bugzilla.redhat.com/show_bug.cgi?id=2450590WEB
- https://github.com/open-cluster-management-io/OCMPACKAGE
- https://github.com/open-cluster-management-io/ocm/commit/9e70cc1e21a15239c81111062c0b37df4b5a8026WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-4740ADVISORY
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