CVE-2026-4740

Published: Apr 7, 2026Modified: Jul 15, 2026

8.2

Vector

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Exploitability: 1.5 / Impact: 6.0

Source: secalert@redhat.com (Secondary)

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 (1)

Products: Redhat: Advanced Cluster Management For Kubernetes

1 product

Advanced Cluster Management For Kubernetes

Configuration A

1 vulnerable

Vulnerable Software	Affected Versions
Redhat Advanced Cluster Management For Kubernetes	All versions

Related CWEs

Improper Certificate Validation

The product does not validate, or incorrectly validates, a certificate.

References (6)

https://access.redhat.com/security/cve/CVE-2026-4740

Source: secalert@redhat.com

Vendor Advisory

https://blog.arfevrier.fr/open-cluster-management-cross-cluster-escape/

Source: secalert@redhat.com

ExploitThird Party Advisory

https://bugzilla.redhat.com/show_bug.cgi?id=2450590

Source: secalert@redhat.com

Issue TrackingVendor Advisory

https://access.redhat.com/security/cve/CVE-2026-4740

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

Vendor Advisory

https://bugzilla.redhat.com/show_bug.cgi?id=2450590

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

Issue TrackingVendor Advisory

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4740.json

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

Timeline

No history available yet.