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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | multicluster engine for Kubernetes 2.1 | — | — |
| Red Hat | multicluster engine for Kubernetes 2.11 | — | — |
| Red Hat | multicluster engine for Kubernetes 2.6 | — | — |
| Red Hat | multicluster engine for Kubernetes 2.8 | — | — |
| Red Hat | multicluster engine for Kubernetes 2.9 | — | — |
| Red Hat | Multicluster Engine for Kubernetes | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260723T184607-160000.1.1 | openSUSE-SU-2026:21483-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | open-cluster-management.io/ocm | < 1.2.1 | 1.2.1 | GHSA-q4gv-pjmh-c735 |
Advisories 1
- openSUSE-SU-2026:21483-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Jul 31, 2026
References
- RHSA-2026:11414 vendor-advisory
- RHSA-2026:13542 vendor-advisory
- RHSA-2026:13853 vendor-advisory
- RHSA-2026:8218 vendor-advisory
- RHSA-2026:9848 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-4740 vdb-entry
- https://blog.arfevrier.fr/open-cluster-management-cross-cluster-escape/
- RHBZ#2450590 issue-tracking