Bug 2527100 (CVE-2026-84638)

A flaw was found in Red Hat Ansible Automation Platform's automation- controller. When attaching an instance group to a schedule or a workflow job template node through the dedicated API relationship endpoint, the controller verifies only that the requesting user can read (view) the instance group, rather than that they hold use permission on it, unlike every other instance group assignment in the product. An authenticated user with read-only visibility of an instance group -- for example a system auditor -- can attach a use-restricted instance group, including the control plane group or another tenant's container group, to a schedule or workflow node they control. Their playbook then executes on the control plane node or within another tenant's execution environment, leading to privilege escalation and, in the control plane case, full compromise of the platform.