Description

A flaw was found in the governance-policy-addon-controller component of Red Hat Advanced Cluster Management for Kubernetes. A user with permissions to annotate the namespaced ManagedClusterAddOn resource can override the governance-policy container image. This allows an attacker to run a controlled image with cluster-admin privileges on the managed cluster, leading to arbitrary code execution and privilege escalation.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-18T15:17:00.140Z",
  "pubdate": "2026-08-18T15:17:00.140Z",
  "executiveSummary": "A privilege escalation vulnerability has been identified within the governance-policy-addon-controller component of Red Hat Advanced Cluster Management for Kubernetes. The vulnerability allows an authenticated malicious actor with specific annotation permissions on the namespaced ManagedClusterAddOn resource to override the governance-policy container image. Successful exploitation of this flaw leads to arbitrary code execution with cluster-admin privileges on the targeted managed cluster, representing a severe risk to the confidentiality, integrity, and availability of the affected Kubernetes environments. The attack requires initial user permissions to modify annotations on the specified namespaced resource, enabling the execution of a fully controlled malicious container image within the privileged execution context of the managed cluster architecture.",
  "technicalDetails": "The root cause of the vulnerability resides in insufficient input validation and access control enforcement within the governance-policy-addon-controller component of Red Hat Advanced Cluster Management for Kubernetes. Specifically, the controller processes annotations applied to the namespaced ManagedClusterAddOn resource without adequately restricting modifications that dictate container image references.\nAn attacker possessing authorization to annotate the namespaced ManagedClusterAddOn resource can supply manipulated annotation values designed to substitute the legitimate governance-policy container image with a malicious, user-controlled image payload. Upon processing these annotations, the governance-policy-addon-controller deploys or updates the underlying Kubernetes resources using the attacker-specified image reference.\nThe attack flow proceeds as follows: First, the adversary authenticates to the Kubernetes API server with permissions restricted to the namespaced ManagedClusterAddOn resource. Second, the adversary applies crafted annotations to this resource. Third, the governance-policy-addon-controller reconciles the resource state, extracts the overridden image path, and schedules the malicious container execution on the managed cluster.\nBecause the governance-policy component typically operates with elevated privileges necessary for policy enforcement and cluster management, executing a controlled image within this context inherits those elevated permissions. Consequently, the payload executes with cluster-admin privileges, enabling full administrative control over the managed cluster, cluster-wide resource manipulation, potential lateral movement, and complete compromise of workloads running on the node or cluster."
}