s2Member <= 260127 - Unauthenticated Privilege Escalation via Account Takeover

The s2Member plugin for WordPress is vulnerable to privilege escalation via account takeover in all versions up to, and including, 260127. This is due to the plugin not properly validating a user's identity prior to updating their password. This makes it possible for unauthenticated attackers to change arbitrary user's passwords, including administrators, and leverage that to gain access to their account.