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.
References8
- access.redhat.com/errata/RHSA-2026:59556
- access.redhat.com/errata/RHSA-2026:59557
- access.redhat.com/errata/RHSA-2026:59558
- access.redhat.com/errata/RHSA-2026:59559
- access.redhat.com/errata/RHSA-2026:59579
- access.redhat.com/errata/RHSA-2026:59593
- access.redhat.com/security/cve/CVE-2026-73266
- bugzilla.redhat.com/show_bug.cgi?id=2514217
Metrics
- CVSS 3.1
-
7.1
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N - EPSS — exploit probability
- 0% percentile: 29 · as of 12 November 2026
- CWE
- CWE-441
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.