The Tutor LMS Pro plugin for WordPress is vulnerable to authentication bypass in all versions up to, and including, 3.9.5 via the Social Login addon. This is due to the plugin failing to verify that the email provided in the authentication request matches the email from the validated OAuth token. This makes it possible for unauthenticated attackers to log in as any existing user, including administrators, by supplying a valid OAuth token from their own account along with the victim's email address.