CVE-2026-4740: Open Cluster Management (OCM): Cross-cluster privilege escalation via improper Kubernetes client certificate renewal validation
(updated )
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.
References
- access.redhat.com/security/cve/CVE-2026-4740
- blog.arfevrier.fr/open-cluster-management-cross-cluster-escape
- bugzilla.redhat.com/show_bug.cgi?id=2450590
- github.com/advisories/GHSA-q4gv-pjmh-c735
- github.com/open-cluster-management-io/OCM
- github.com/open-cluster-management-io/ocm/commit/9e70cc1e21a15239c81111062c0b37df4b5a8026
- nvd.nist.gov/vuln/detail/CVE-2026-4740
Code Behaviors & Features
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