CVE-2026-72508 is a critical security flaw in Red Hat Advanced Cluster Management for Kubernetes 2's multicloud-operators-subscription component. A namespace administrator can exploit this vulnerability by creating Subscription Custom Resources that utilize a highly privileged ServiceAccount (application-manager addon) with broad wildcard permissions. This confused-deputy attack allows the tenant to deploy arbitrary cluster-scoped resources, resulting in privilege escalation and potential arbitrary code execution across the entire Kubernetes cluster. The default configuration grants excessive permissions to the application-manager ServiceAccount, significantly expanding the attack surface beyond the namespace level. Red Hat's advisory advises administrators to apply a least-privilege RBAC configuration by using the addon/manifests/permission/role.yaml manifest to restrict these permissions and reduce risk.

The vulnerability allows a namespace-admin tenant to escalate privileges from namespace scope to cluster scope by leveraging a highly privileged ServiceAccount with wildcard permissions. This can lead to arbitrary code execution, unauthorized deployment of cluster-scoped resources, and full compromise of the Kubernetes cluster's confidentiality, integrity, and availability. The blast radius is significantly increased beyond typical namespace boundaries, posing a critical risk to cluster security.

Red Hat recommends configuring the application-manager addon in Red Hat Advanced Cluster Management for Kubernetes to use the least-privilege RBAC variant. This involves applying the addon/manifests/permission/role.yaml configuration to restrict the permissions granted to the application-manager ServiceAccount. Administrators should consult Red Hat documentation for detailed instructions on applying custom RBAC configurations for RHACM addons. After applying the configuration, a restart or reload of affected components may be required for changes to take effect. No official patch or fix version is currently stated; patch status is not yet confirmed — check the Red Hat advisory for updates.