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{"bugzilla": {"description": "clusterclaims-controller: clusterclaims-controller: tenant-controlled ClusterClaim labels propagated to ManagedCluster enabling cross-tenant ManagedClusterSet join", "id": "2514217", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2514217"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.1", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N", "status": "draft"}, "cwe": "CWE-441", "details": ["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."], "mitigation": {"lang": "en:us", "value": "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."}, "name": "CVE-2026-73266", "package_state": [{"cpe": "cpe:/a:redhat:multicluster_engine", "fix_state": "Affected", "package_name": "multicluster-engine/clusterclaims-controller-rhel9", "product_name": "Multicluster Engine for Kubernetes"}], "public_date": "2026-08-11T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-73266\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-73266"], "statement": "This Important flaw in Multicluster Engine for Kubernetes' clusterclaims-controller allows a tenant to propagate arbitrary labels from a ClusterClaim to a ManagedCluster object. This enables unauthorized cross-tenant ManagedClusterSet joins, leading to policy and workload injection into victim clusters. The vulnerability breaks tenant isolation, granting an attacker control over resources belonging to other tenants.", "threat_severity": "Important"}