CVE-2026-10090: Red Hat Advanced Cluster Management For Kubernetes 2.11
Critical severity, CVSS 9.0. EPSS: 0.6% chance of exploitation in the next 30 days.
A flaw was found in the Application Subscription controller (multicluster-operators-subscription) of Red Hat Advanced Cluster Management for Kubernetes (ACM). A user with namespace-scoped "edit" privileges in an ACM hub namespace can create a Channel resource pointing to a Helm repository they control and a Subscription resource referencing it. The app-subscription controller fetches and applies the Helm chart contents with its own elevated authority, without verifying whether the subscription creator holds the "open-cluster-management:subscription-admin" role and without restricting applied resources to the subscription namespace. This allows the attacker to include cluster-scoped resources in the Helm chart, such as a ClusterRoleBinding granting the attacker's ServiceAccount the "cluster-admin" ClusterRole. Successful exploitation results in full cluster-admin privilege escalation. This contradicts the ACM documentation which states that non-subscription-admin users should have resources deployed into the subscription namespace only.
Affected products
- Red Hat Red Hat Advanced Cluster Management For Kubernetes 2.11: before 1787263584 (fixed in 1787263584)
- Red Hat Red Hat Advanced Cluster Management For Kubernetes 2.13: before 1787263693 (fixed in 1787263693)
- Red Hat Red Hat Advanced Cluster Management For Kubernetes 2.14: before 1787170830 (fixed in 1787170830)
- Red Hat Red Hat Advanced Cluster Management For Kubernetes 2.15: before 1787240030 (fixed in 1787240030)
- Red Hat Red Hat Advanced Cluster Management For Kubernetes 2.16: before 1787242321 (fixed in 1787242321)
- Red Hat Red Hat Advanced Cluster Management For Kubernetes 2.17: before 1787242108 (fixed in 1787242108)
Published 2026-08-05. Last modified 2026-09-08.