multicluster engine for Kubernetes 2.1 vulnerability

A flaw was found in the clusterclaims-controller component of multicluster engine (MCE). A tenant with standard permissions to create and delete ClusterClaim resources can exploit this by manipulating the `spec.namespace` field. This allows the tenant to specify and delete any ManagedCluster, including the hub's local-cluster or other tenants' clusters, due to a missing ownership check. This vulnerability can lead to a denial of service by enabling unauthorized deletion of ManagedClusters.

Published 21 Aug 2026Updated 5 Sep 20268 sources
CVSS 7.7

What happened

A flaw was found in the clusterclaims-controller component of multicluster engine (MCE). A tenant with standard permissions to create and delete ClusterClaim resources can exploit this by manipulating the `spec.namespace` field. This allows the tenant to specify and delete any ManagedCluster, including the hub's local-cluster or other tenants' clusters, due to a missing ownership check. This vulnerability can lead to a denial of service by enabling unauthorized deletion of ManagedClusters.

Affected versions

multicluster engine for Kubernetes 2.1: See vendor advisory Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.