CVE-2026-4740

HIGH8.2

Rhacm: open cluster management (ocm): cross-cluster privilege escalation via improper kubernetes client certificate renewal validation

Published Apr 7, 2026

Modified 1 weeks ago

Details

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

WEB

https://access.redhat.com/security/cve/CVE-2026-4740

WEB

https://blog.arfevrier.fr/open-cluster-management-cross-cluster-escape/

WEB

https://bugzilla.redhat.com/show_bug.cgi?id=2450590

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-4740

CVSS Analysis

CVSS v3.1

8.2