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🛡️ CVE-2026-4740 — advanced-cluster-management-for-kubernet

🟠 CVSS 8.2 — High ⚠️ Exploit Public CWE-295 NVD
8.2
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Open Cluster Management (OCM): Cross-cluster privilege escalation via improper Kubernetes client certificate renewal validation

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.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs administrative privileges on the target. No user interaction is required. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality high, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

  • Attack vector: Local — a local account, shell or session on the host is needed.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: High — administrative rights are needed first.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Changed — a successful attack reaches components beyond the vulnerable one.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: High — total loss, or loss the attacker controls.

Weakness class

CVE-2026-4740 is classified as CWE-295: Improper Certificate Validation. A TLS certificate is accepted without proper verification, so a man-in-the-middle can present their own.

Affected software

CVE-2026-4740 is recorded against 2 packages.

  • advanced-cluster-management-for-kubernetes
  • open-cluster-management.io/ocm

Timeline and source

Published on 7 April 2026 and last revised on 19 August 2026. A public exploit is known to exist, which raises the urgency of patching considerably. Record sourced from NVD.

References

access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
blog.arfevrier.fr
bugzilla.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
access.redhat.com
bugzilla.redhat.com
security.access.redhat.com

Other advisories for this package

advanced-cluster-management-for-kubernetes has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-295: Improper Certificate Validation) in other software:

Details

Severity HIGH
CVSS Score 8.2
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
CWE CWE-295
Public Exploit ⚠️ Yes
Source NVD
Published 2026-04-07
Updated 2026-08-20
Modified 2026-08-19
Fix URL N/A

Affected Packages

Software From version Fixed in
advanced-cluster-management-for-kubernetes
open-cluster-management.io/ocm

References

Issue Tracking, Vendor Advisory https://bugzilla.redhat.com/show_bug.cgi?id=2450590
Issue Tracking, Vendor Advisory https://bugzilla.redhat.com/show_bug.cgi?id=2450590

Similar Threats

Exploit Protection

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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