CVE-2026-73266

Clusterclaims-controller: confused deputy: tenant-controlled clusterclaim labels propagated to managedcluster, enabling cross-tenant managedclusterset join

Published Aug 13, 2026 CVSS 3.1 · 7.1 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

Vendor Workaround

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Title Clusterclaims-controller: clusterclaims-controller: tenant-controlled clusterclaim labels propagated to managedcluster enabling cross-tenant managedclusterset join Clusterclaims-controller: confused deputy: tenant-controlled clusterclaim labels propagated to managedcluster, enabling cross-tenant managedclusterset join
Type Values Removed Values Added
CPEs cpe:/a:redhat:multicluster_engine:2.10::el9
cpe:/a:redhat:multicluster_engine:2.6::el9
cpe:/a:redhat:multicluster_engine:2.8::el9
cpe:/a:redhat:multicluster_engine:2.9::el9
References
Type Values Removed Values Added
CPEs cpe:/a:redhat:multicluster_engine:2.17::el9
References
Type Values Removed Values Added
CPEs cpe:/a:redhat:multicluster_engine cpe:/a:redhat:multicluster_engine:2.11::el9
References
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Redhat multicluster Engine For Kubernetes
Vendors & Products Redhat multicluster Engine For Kubernetes
Type Values Removed Values Added
Description 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.
Title Clusterclaims-controller: clusterclaims-controller: tenant-controlled clusterclaim labels propagated to managedcluster enabling cross-tenant managedclusterset join
First Time appeared Redhat
Redhat multicluster Engine
Weaknesses CWE-441
CPEs cpe:/a:redhat:multicluster_engine
Vendors & Products Redhat
Redhat multicluster Engine
References
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Sep 29, 2026, 7:41 PM
Reserved
Aug 11, 2026, 5:22 PM
Status
Awaiting Analysis
Published
Aug 13, 2026, 5:17 PM
Modified
Sep 29, 2026, 8:17 PM
Severity
Important
Public date
Aug 11, 2026, 12:00 AM