Authentication Bypass Vulnerability in Divi Membership Plugin for WordPress

CVE-2026-19660

What is CVE-2026-19660?

The Divi Membership plugin for WordPress has a critical vulnerability that allows unauthenticated attackers to bypass authentication processes, enabling them to log in as any existing user, including administrators. This issue arises from a flaw in how the process_paypal_callback function handles the paypal_param GET parameter, which lacks essential validation measures such as IPN validation, cryptographic signature checks, and nonce verification. By exploiting this vulnerability, attackers can tamper with the user ID passed to wp_set_current_user() and wp_set_auth_cookie(), leading to unauthorized access and potential full site control. The problematic design persists as the PayPal gateway class is always instantiated, ensuring the vulnerability is present on every front-end request, whether PayPal is active or not.

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