ReviewCritical

CVE-2026-66788

Red Hat Red Hat Advanced Cluster Management for Kubernetes 2

A flaw was found in Lighthouse. A remote attacker, by compromising a spoke cluster, can exploit a vulnerability where the destination namespace for resource injection is derived from an attacker-controlled label or annotation on the broker object. This allows the attacker to inject unauthorized EndpointSlices and ServiceImports into any namespace on peer clusters, including critical system namespaces like kube-system and openshift-*. This could lead to privilege escalation or other forms of system compromise within the cluster.

CVSS: 9.9
EPSS: -
CISA KEV: Not listed
Published: 2026.08.21

PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability-

Technical severityCVSS 9.9

Vulnerability overview

Affected product and versions

Product: Red Hat Red Hat Advanced Cluster Management for Kubernetes 2
Affected versions: See the vendor advisory and NVD configuration data
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Red Hat Red Hat Advanced Cluster Management for Kubernetes 2 and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CWE: CWE-284