EUVD-2026-60951
GHSA-xh6j-xcjj-j38g
Severity by source
AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
S:C assigned independently because exploitation on the hub yields cluster-admin on separate managed clusters, crossing Kubernetes security domain boundaries.
Primary rating from Vendor (redhat).
CVSS VectorVendor: redhat
Lifecycle Timeline
2DescriptionCVE.org
A flaw was found in the governance-policy-addon-controller component of Red Hat Advanced Cluster Management for Kubernetes. A user with permissions to annotate the namespaced ManagedClusterAddOn resource can override the governance-policy container image. This allows an attacker to run a controlled image with cluster-admin privileges on the managed cluster, leading to arbitrary code execution and privilege escalation.
Articles & Coverage 1
AnalysisAI
Privilege escalation and arbitrary code execution in Red Hat Advanced Cluster Management for Kubernetes (RHACM) allows an authenticated low-privilege user to hijack the governance-policy container image across managed clusters. By annotating the namespaced ManagedClusterAddOn resource - a permission that may be granted to non-administrative users - the attacker causes the governance-policy-addon-controller to deploy a malicious, attacker-controlled image running with cluster-admin privileges on every managed cluster under the hub's control. No public exploit or CISA KEV listing has been confirmed at time of analysis, but the low attack complexity and high impact across cluster boundaries make this a prioritized patching target for multi-cluster RHACM deployments.
Technical ContextAI
Red Hat ACM's governance framework enforces policy across managed Kubernetes clusters using the Open Cluster Management (OCM) add-on architecture. The governance-policy-addon-controller reconciles ManagedClusterAddOn resources on the hub cluster to deploy policy agent containers onto each spoke (managed) cluster. The root cause is CWE-20 (Improper Input Validation): the controller accepts an annotation on the ManagedClusterAddOn resource as a mechanism to override the governance-policy container image reference without sufficient authorization or integrity checks. This design flaw allows any user with Kubernetes RBAC permission to annotate that namespaced resource to substitute a legitimate image with an arbitrary one. Because the deployed image inherits cluster-admin privileges on the managed cluster - a requirement of the governance subsystem - the blast radius of the flaw crosses security domain boundaries between hub and spoke clusters.
Affected ProductsAI
The affected component is the governance-policy-addon-controller within Red Hat Advanced Cluster Management for Kubernetes. Specific affected version ranges are not enumerated in the provided CVE data; the authoritative list of affected RHACM versions is maintained in the Red Hat security advisory at https://access.redhat.com/security/cve/CVE-2026-66793 and the corresponding Bugzilla entry at https://bugzilla.redhat.com/show_bug.cgi?id=2507538. Organizations should consult those sources directly for version-specific applicability, including any errata for OpenShift-bundled ACM distributions.
RemediationAI
No exact patched version number is specified in the provided data - patch availability and exact fix versions must be confirmed via the Red Hat advisory at https://access.redhat.com/security/cve/CVE-2026-66793 and monitored via Red Hat's errata system. As an immediate compensating control, restrict Kubernetes RBAC permissions to annotate the ManagedClusterAddOn resource (specifically the patch and update verbs) exclusively to cluster-administrators and the RHACM service accounts - removing this permission from all developer, operator, or namespace-scoped roles. This trades off some operational flexibility for annotation-based workflows but directly eliminates the exploitation vector. Additionally, audit existing ManagedClusterAddOn resource annotations across all namespaces for unexpected image references, as evidence of prior exploitation. Enabling OPA/Gatekeeper or Kyverno admission control policies to reject ManagedClusterAddOn annotations containing non-approved image registries provides a defence-in-depth layer with minimal operational disruption.
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View allVendor StatusVendor
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