The Formidable Forms WordPress plugin before 6.32.1 does not properly validate the status of a PayPal subscription payment before marking it complete, allowing unauthenticated users to bypass payment and trigger paid form actions — such as digital content access, license delivery, and membership activation — without being charged.
https://wpscan.com/vulnerability/dbee54f6-898f-436a-9f72-f2248931ea12/