Vulnerability Description
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.
CVSS Score
CRITICAL
Related Weaknesses (CWE)
References
- https://access.redhat.com/security/cve/CVE-2026-10090
- https://bugzilla.redhat.com/show_bug.cgi?id=2483292
FAQ
What is CVE-2026-10090?
CVE-2026-10090 is a vulnerability with a CVSS score of 9.9 (CRITICAL). 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" privi...
How severe is CVE-2026-10090?
CVE-2026-10090 has been rated CRITICAL with a CVSS base score of 9.9/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-10090?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.