An access control vulnerability was discovered in Grafana OSS where an Organization administrator could permanently delete the Server administrator account. This vulnerability exists in the DELETE /api/org/users/ endpoint.

The vulnerability can be exploited when:

1. An Organization administrator exists

2. The Server administrator is either:

   - Not part of any organization, or
   - Part of the same organization as the Organization administrator
Impact:

- Organization administrators can permanently delete Server administrator accounts

- If the only Server administrator is deleted, the Grafana instance becomes unmanageable

- No super-user permissions remain in the system

- Affects all users, organizations, and teams managed in the instance

The vulnerability is particularly serious as it can lead to a complete loss of administrative control over the Grafana instance.