Description
A flaw was found in the Application Subscription controller (multicluster-operators-subscription) of Red Hat Advanced Cluster Management for Kubernetes (ACM). A user with namespace-scoped "edit" privileges in an ACM hub namespace can create a Channel resource pointing to a Helm repository they control and a Subscription resource referencing it. The app-subscription controller fetches and applies the Helm chart contents with its own elevated authority, without verifying whether the subscription creator holds the "open-cluster-management:subscription-admin" role and without restricting applied resources to the subscription namespace. This allows the attacker to include cluster-scoped resources in the Helm chart, such as a ClusterRoleBinding granting the attacker's ServiceAccount the "cluster-admin" ClusterRole. Successful exploitation results in full cluster-admin privilege escalation. This contradicts the ACM documentation which states that non-subscription-admin users should have resources deployed into the subscription namespace only.
References8
- access.redhat.com/errata/RHSA-2026:60386
- access.redhat.com/errata/RHSA-2026:60387
- access.redhat.com/errata/RHSA-2026:60388
- access.redhat.com/errata/RHSA-2026:60389
- access.redhat.com/errata/RHSA-2026:60390
- access.redhat.com/errata/RHSA-2026:60391
- access.redhat.com/security/cve/CVE-2026-10090
- bugzilla.redhat.com/show_bug.cgi?id=2483292
Metrics
- CVSS 3.1
-
9.0
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:L - EPSS — exploit probability
- 1% percentile: 48 · as of 13 November 2026
- CWE
- CWE-267
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