The BuddyForms plugin for WordPress is vulnerable to Email Verification Bypass in all versions up to, and including, 2.8.9 via the use of an insufficiently random activation code. This makes it possible for unauthenticated attackers to bypass the email verification.
https://plugins.trac.wordpress.org/browser/buddyforms/tags/2.8.9/includes/wp-insert-user.php#L334