Cross-namespace resource injection via broker labels

Improper access control in Lighthouse in Red Hat Advanced Cluster Management for Kubernetes allows remote attackers to inject resources via broker metadata. The lighthouse-agent derives the destination namespace for replicated EndpointSlices and ServiceImports from a broker label or annotation that a compromised spoke cluster can control, and it does not validate that namespace before writing the objects. Reachability requires control of a spoke cluster rather than an external unauthenticated path, but successful exploitation can place service-discovery objects in peer namespaces, including kube-system and openshift-*, enabling privilege escalation, traffic disruption, or broader cluster compromise.