PT-2026-30871 · Unknown · Open Cluster Management+1

Arnaud Fevrier · Published 2026-04-07 · Updated 2026-04-09 · CVE-2026-4740

Positive Technologies (AI Summary)

CVSS v3.1

8.2

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Open Cluster Management (OCM) (affected versions not specified)

Description A flaw exists due to improper validation of Kubernetes client certificate renewal. This allows a managed cluster administrator to forge a client certificate that can be approved by the OCM controller, potentially leading to cross-cluster privilege escalation and control over other managed clusters, including the hub cluster.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

LPE

Improper Certificate Validation

Weakness Enumeration

CWE-295

Related Identifiers

CVE-2026-4740

GHSA-Q4GV-PJMH-C735

Affected Products

Kubernetes

Open Cluster Management

References · 9

• 🔥 https://blog.arfevrier.fr/open-cluster-management-cross-cluster-escape · Exploit
• https://bugzilla.redhat.com/show_bug.cgi?id=2450590 · Vendor Advisory
• https://access.redhat.com/security/cve/CVE-2026-4740 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-4740 · Security Note
• https://osv.dev/vulnerability/GHSA-q4gv-pjmh-c735 · Vendor Advisory
• https://github.com/open-cluster-management-io/OCM · Note
• https://github.com/open-cluster-management-io/ocm/commit/9e70cc1e21a15239c81111062c0b37df4b5a8026 · Note
• https://twitter.com/pulsepatchio/status/2042071397405749614 · Twitter Post
• https://twitter.com/CVEnew/status/2041603235908092075 · Twitter Post