# CVE-2026-73266

## Summary

- **CVE ID:** CVE-2026-73266
- **Severity:** HIGH
- **CVSS Score:** 7.1 (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N)
- **CWE:** CWE-441
- **Published:** Aug 13, 2026
- **Last Modified:** Sep 8, 2026

## 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.

## Affected Products

- Red Hat — multicluster engine for Kubernetes 2.9.0 (1787195995)
- Red Hat — multicluster engine for Kubernetes 2.11 (1787239442)
- Red Hat — multicluster engine for Kubernetes 2.17 (1786577950)
- Red Hat — multicluster engine for Kubernetes 2.10 (1787196014)
- Red Hat — multicluster engine for Kubernetes 2.6 (1787259112)
- Red Hat — multicluster engine for Kubernetes 2.8 (1787259059)
- Red Hat — multicluster engine for Kubernetes 2.9 (1787195995)
- Red Hat — multicluster engine for Kubernetes 2.1 (1787196014)

## References

- [CNA](https://access.redhat.com/security/cve/CVE-2026-73266)
- [CNA](https://bugzilla.redhat.com/show_bug.cgi?id=2514217)
- [CNA](https://access.redhat.com/errata/RHSA-2026:59556)
- [CNA](https://access.redhat.com/errata/RHSA-2026:59593)
- [CNA](https://access.redhat.com/errata/RHSA-2026:59557)
- [CNA](https://access.redhat.com/errata/RHSA-2026:59558)
- [CNA](https://access.redhat.com/errata/RHSA-2026:59559)
- [CNA](https://access.redhat.com/errata/RHSA-2026:59579)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.21%
- **EPSS Percentile:** 11.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._