Home/CVE/A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM).
CVE

CVE-2026-4740

A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM).

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.

HIGH · CVSS 8.2 EPSS 0.00012
Act now
  • Public exploit or PoC is available
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-295Improper Certificate Validation
▤

Affected Products & Versions

1
redhat advanced cluster management for kubernetesall versions
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Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
Go open-cluster-management.io/ocm HIGH fixed in 1.2.1
⚠

Public Exploits & PoCs

1
pocblog.arfevrier.fr · open-cluster-management-cross-cluster-escapeblog.arfevrier.fr
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Scoring & Timeline

8.2
HIGH · CVSS v3.1 · secalert@redhat.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD07 Apr 2026 · 03:17 PM
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
total
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://access.redhat.com/security/cve/CVE-2026-4740Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2450590Issue TrackingVendor Advisory
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