How severe is CVE-2026-4740?

CVE-2026-4740 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-4740 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-4740?

CVE-2026-4740 affects Redhat Advanced Cluster Management For Kubernetes. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-4740?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-4740 have an EU (EUVD) identifier?

Yes. CVE-2026-4740 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19690.

When was CVE-2026-4740 published?

CVE-2026-4740 was published on 2026-04-07 and last updated on 2026-06-30.

CVE-2026-4740

CVE-2026-4740 is a high-severity vulnerability in Redhat Advanced Cluster Management For Kubernetes with a CVSS 3.x base score of 8.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-295.

Key facts

Severity: High (CVSS 3.x base score 8.2)
EPSS exploit prediction: 0% (2nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-19690
Weakness: CWE-295
Affected product: Redhat Advanced Cluster Management For Kubernetes
Published: 2026-04-07
Last modified: 2026-06-30

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.

Frequently asked questions

What is CVE-2026-4740?: 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 severe is CVE-2026-4740?: CVE-2026-4740 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-4740 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-4740?: CVE-2026-4740 affects Redhat Advanced Cluster Management For Kubernetes. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-4740?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-4740 have an EU (EUVD) identifier?: Yes. CVE-2026-4740 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19690.
When was CVE-2026-4740 published?: CVE-2026-4740 was published on 2026-04-07 and last updated on 2026-06-30.

References

Affected products (1)

cpe:2.3:a:redhat:advanced_cluster_management_for_kubernetes:-:*:*:*:*:*:*:*

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