The User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder WordPress plugin contains a missing authorization vulnerability in the confirm_payment() function. This flaw allows unauthenticated attackers to modify data by bypassing payment processing and activating paid memberships without proper validation. The vulnerability affects all versions up to and including 5.2.0. No patch or official remediation is currently documented.

An attacker without authentication can bypass payment processing controls and activate paid memberships fraudulently. This leads to unauthorized access to paid content or services, resulting in potential revenue loss and unauthorized privilege escalation within the affected WordPress site.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, consider restricting access to the confirm_payment() function or implementing additional authorization checks as a temporary mitigation.