PT-2026-30871 · Red Hat · Multicluster Engine For Kubernetes

Published 2026-04-07 · Updated 2026-04-07 · CVE-2026-4740

NVD

CVSS v3.1

8.2

High

AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

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.

Fix

Improper Certificate Validation

Weakness Enumeration

CWE-295

Related Identifiers

CVE-2026-4740

Affected Products

Multicluster Engine For Kubernetes

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-4740 · Security Note
• https://bugzilla.redhat.com/show_bug.cgi?id=2450590 · Note
• https://access.redhat.com/security/cve/CVE-2026-4740 · Note
• https://blog.arfevrier.fr/open-cluster-management-cross-cluster-escape · Note