InvoicePlane: Failure to Revoke Administrative Privileges After Role Downgrade

InvoicePlane is a self-hosted open source application for managing invoices, clients, and payments. Prior to 1.7.2, InvoicePlane fails to revoke administrative privileges after a role downgrade because Admin_Controller trusts the user_type snapshot stored in an existing session instead of revalidating ip_users.user_type. When one administrator downgrades another account, the target's active session continues to authorize administrative requests. The downgraded user can use Users::form() to set user_type back to 1, restoring the database role and making the privilege escalation persistent. This vulnerability is fixed in 1.7.2.