Executive brief
myCred is a WordPress plugin that manages in-site virtual currency and handles payments through the buyCRED add-on and PayPal integration. The plugin fails to verify that incoming PayPal payment notifications are actually destined for the site's merchant account, allowing attackers to trick the system into crediting a user with virtual currency by sending fake payment confirmations from their own PayPal account. This could result in unauthorized free currency generation and financial loss for site operators who rely on legitimate purchases.
Technical details
The vulnerability is a payment gateway notification validation bypass (CWE-346) in the myCred plugin's PayPal IPN handler. The buyCRED payment gateway accepts Instant Payment Notifications (IPN) from PayPal but fails to verify that the "receiver_email" or "business" field in the IPN matches the site's configured merchant account email. An unauthenticated attacker can initiate a purchase on the target site (which generates a pending purchase with a public ID), then send a crafted IPN from their own PayPal account with the same purchase ID and correct transaction amount, causing the site to credit the currency as if payment was received. The attack is network-accessible and requires no authentication; the attacker only needs their own PayPal account. Fixed in version 3.2.5; versions 3.2.3 and 3.2.4 reverted the original fix from 3.2.2.
Affected products
- myCred myCred before 3.2.5
Timeline
- 2026-08-17: disclosed
- 2026-08-21: patched: Fixed in version 3.2.5