CVE-2026-73266: Red Hat Multicluster Engine For Kubernetes 2.10

High severity, CVSS 7.1. EPSS: 0.4% chance of exploitation in the next 30 days.

A flaw was found in the clusterclaims-controller component of Multicluster Engine (MCE). An authenticated tenant can exploit this vulnerability by manipulating ClusterClaim labels. This allows the tenant to force a cluster to join a ManagedClusterSet belonging to another tenant. Such unauthorized access could enable the injection of policies and workloads into other tenants' clusters.

Affected products

• Red Hat Multicluster Engine For Kubernetes 2.10: before 1787196014 (fixed in 1787196014)
• Red Hat Multicluster Engine For Kubernetes 2.11: before 1787239442 (fixed in 1787239442)
• Red Hat Multicluster Engine For Kubernetes 2.17: before 1786577950 (fixed in 1786577950)
• Red Hat Multicluster Engine For Kubernetes 2.6: before 1787259112 (fixed in 1787259112)
• Red Hat Multicluster Engine For Kubernetes 2.8: before 1787259059 (fixed in 1787259059)
• Red Hat Multicluster Engine For Kubernetes 2.9: before 1787195995 (fixed in 1787195995)

Published 2026-08-13. Last modified 2026-09-29.