High severity · published Aug 13, 2026
CVE-2026-73266
Clusterclaims-controller: confused deputy: tenant-controlled clusterclaim labels propagated to managedcluster, enabling cross-tenant managedclusterset join
7.1
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
Attack vector
Network
Complexity
High
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 29% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ME
multicluster engine for Kubernetes 2.10 · Red Hat
All versions, or not specified · source: vendor
ME
multicluster engine for Kubernetes 2.11 · Red Hat
All versions, or not specified · source: vendor
ME
multicluster engine for Kubernetes 2.17 · Red Hat
All versions, or not specified · source: vendor
ME
multicluster engine for Kubernetes 2.6 · Red Hat
All versions, or not specified · source: vendor
ME
multicluster engine for Kubernetes 2.8 · Red Hat
All versions, or not specified · source: vendor
ME
multicluster engine for Kubernetes 2.9 · Red Hat
All versions, or not specified · source: vendor
Affected product
ME
multicluster engine for Kubernetes 2.10
Red Hat
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-73266
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-73266
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:59556
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:59557
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:59558
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:59559
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:59579
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:59593
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