Vulnerability Description
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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Redhat | Advanced Cluster Management For Kubernetes | - |
Related Weaknesses (CWE)
References
- https://access.redhat.com/security/cve/CVE-2026-4740Vendor Advisory
- https://blog.arfevrier.fr/open-cluster-management-cross-cluster-escape/ExploitThird Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2450590Issue TrackingVendor Advisory
FAQ
What is CVE-2026-4740?
CVE-2026-4740 is a vulnerability with a CVSS score of 8.2 (HIGH). 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 cl...
How severe is CVE-2026-4740?
CVE-2026-4740 has been rated HIGH with a CVSS base score of 8.2/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-4740?
Check the references section above for vendor advisories and patch information. Affected products include: Redhat Advanced Cluster Management For Kubernetes.