CVE-2026-4740
Open Cluster Management (OCM): Cross-cluster privilege escalation via improper Kubernetes client certificate renewal validation
8.2
HIGH
CVSS 3.1
EPSS 0.01%
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.
How to fix CVE-2026-4740
To remediate CVE-2026-4740, upgrade the affected package to a fixed version below.
- —upgrade to 1.2.1 or later
Is CVE-2026-4740 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 1.2.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH8.2 | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H |