The Payment Gateway for PayPal on WooCommerce WordPress plugin before 9.2.1 does not verify that an incoming payment notification was confirmed in the store's configured payment environment or paid to the store's own merchant account before marking an order complete, allowing unauthenticated users to mark their own orders as paid using a genuine transaction from a payment sandbox they control.

The Payment Gateway for PayPal on WooCommerce WordPress plugin before 9.2.1 does not verify that an incoming payment notification was confirmed in the store's configured payment environment or paid to the store's own merchant account before marking an order complete, allowing unauthenticated users to mark their own orders as paid using a genuine transaction from a payment sandbox they control.