CVE-2026-67567: Multicloud-operators-subscription: multicloud-operators-subscription: helmrelease chart applied with controller sa without gvk or namespace restriction
A flaw was found in the multicloud-operators-subscription component of Red Hat Advanced Cluster Management (RHACM). The HelmRelease controller's NewManager() function builds Helm action.Configuration using the controller's own kubeconfig without impersonation or SubjectAccessReview. No GVK filter or namespace coercion is applied, allowing cluster-scoped or cross-namespace Helm chart templates to be applied with the controller's wildcard (//) ServiceAccount privileges. A tenant who can create a HelmRelease CR can achieve arbitrary resource deployment cluster-wide.
Upstream repo: https://github.com/stolostron/multicloud-operators-subscription Audited commit: 48ae4defaa5b719e0664e1de7413c96029c938bc Jira tracker: ACM-38623
Other sources
A flaw was found in the multicloud-operators-subscription component. This vulnerability allows a tenant, who has the ability to create HelmRelease custom resources (CRs), to bypass existing security controls. The system's HelmRelease controller processes Helm chart templates using its own elevated ServiceAccount privileges without proper validation. This enables the tenant to deploy arbitrary resources across the entire cluster, leading to a significant security compromise.
— MITRE
Affected Software
Event History
Frequently Asked Questions
Who can exploit this issue?
A tenant that can create HelmRelease custom resources can exploit it. No user interaction is required, and the attack can be performed over the network according to the supplied vector.
What access could an attacker gain through exploitation?
The HelmRelease controller renders and applies chart templates using its elevated ServiceAccount privileges without adequate GVK or namespace validation. An attacker can use this to deploy arbitrary resources across the cluster, with high impact to confidentiality, integrity, and availability.
Does exploiting this require existing credentials or permissions?
Yes. The attacker needs privileges to create HelmRelease CRs. The provided vector lists privileges required as low, but does not identify the specific role or binding that grants HelmRelease creation.