Authorization Bypass Through User-Controlled Key in the supplier API in Roskus Prospero Flow CRM 4.0.0 through 5.3.1 allows any authenticated user to read and modify another company's supplier record, and to reassign it to their own company, via a PUT request to /api/supplier/{id} setting company_id in the body.
Upgrade to 5.3.2 or later; first tagged release with the fix is v5.5.3. Review the supplier table for altered company_id values and rotate exposed order-portal credentials and bank details.