CVE-2026-4740
Last modified
CVE-2026-4740 is a high-severity vulnerability rated 8.2/10 on the CVSS scale. 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. EPSS estimates a 0.11% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Redhat | Advanced Cluster Management For Kubernetes | All versions |
References
- https://access.redhat.com/security/cve/CVE-2026-4740Vendor Advisory
- https://blog.arfevrier.fr/open-cluster-management-cross-cluster-escape/Exploit, Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2450590Issue Tracking, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
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