The vulnerable version of the Paid Membership Subscriptions WordPress plugin accepts a payment amount and currency supplied by PayPal without verifying that they match the expected amount and currency for the selected membership level. As a result, an unauthenticated user can submit a payment that is lower than the intended price or that uses a different currency, yet the plugin still grants the user full paid‑membership privileges. This constitutes an authorization bypass that allows attackers to obtain premium account features without paying the correct fee.

Any WordPress site that installs Paid Membership Subscriptions before version 3.0.9 is vulnerable. The problem applies to all installations regardless of site size, as long as the plugin is active and PayPal Standard is used for payments.

The CVSS score of 5.3 indicates a moderate impact, but the EPSS score of less than 1% suggests that exploit attempts are unlikely to be widespread at the time of this analysis. The vulnerability is not listed in the CISA KEV catalog. Attackers would need to submit a payment request to the site, which is a relatively low barrier, yet the lack of verification makes the attack path trivial. Because the flaw is purely an authorization error, a successful exploitation yields immediate and permanent access to privileged content or services associated with the paid membership.