CVE-2026-81026: MasterStudy LMS < 3.7.40 - Unauthenticated Payment Bypass via PayPal IPN

The MasterStudy LMS WordPress Plugin WordPress plugin before 3.7.40 does not verify the amount, receiver, currency or status of a payment notification before marking the corresponding order completed, allowing unauthenticated users to complete full-price orders and gain access to paid content by paying only a token amount.