CVE-2026-4740: Red Hat Advanced Cluster Management For Kubernetes

High severity, CVSS 8.2. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Red Hat Advanced Cluster Management For Kubernetes: affected versions not specified

Published 2026-04-07. Last modified 2026-09-08.