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.
Affected products
redhat: advanced cluster management for kubernetes
References10
- access.redhat.com/security/cve/CVE-2026-4740 Vendor Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2450590 Issue TrackingVendor Advisory
- access.redhat.com/security/cve/CVE-2026-4740 Vendor Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2450590 Issue TrackingVendor Advisory
- blog.arfevrier.fr/open-cluster-management-cross-cluster-escape/ ExploitThird Party Advisory
- access.redhat.com/errata/RHSA-2026:11414
- access.redhat.com/errata/RHSA-2026:13542
- access.redhat.com/errata/RHSA-2026:13853
- access.redhat.com/errata/RHSA-2026:8218
- access.redhat.com/errata/RHSA-2026:9848
Metrics
- CVSS 3.1
-
8.2
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 4 · as of 12 November 2026
- CWE
- CWE-295
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