CVE-2026-73266
Clusterclaims-controller: confused deputy: tenant-controlled clusterclaim labels propagated to managedcluster, enabling cross-tenant managedclusterset join
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
7.1
Clusterclaims-controller: confused deputy: tenant-controlled clusterclaim labels propagated to managedcluster, enabling cross-tenant managedclusterset join
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.
- Record
CVE-2026-73266- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N - Weakness
- CWE-441
- Updated
- 2026-11-02
EUVDEUVD-2026-58132
7.1
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.
- Record
EUVD-2026-58132- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-xp42-v53j-r9gh
7.1
A flaw was found in the clusterclaims-controller component of Multicluster Engine (MCE). An...
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.
- Record
GHSA-xp42-v53j-r9gh- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N - Weakness
- CWE-441
- Updated
- 2026-11-02
NVD
7.1
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.
- Record
CVE-2026-73266- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N - Weakness
- CWE-441
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-73266 is a high vulnerability (CVSS 7.1) in Red Hat Multicluster Engine For Kubernetes 2.10, published August 13, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.35%, the 29th percentile. No source names a fixed version.