The Keyy Two Factor Authentication (like Clef) plugin for WordPress is vulnerable to privilege escalation via account takeover in all versions up to, and including, 1.2.3. This is due to the plugin not properly validating a users identity associated with a token generated. This makes it possible for authenticated attackers, with subscriber-level access and above, to generate valid auth tokens and leverage that to auto-login as other accounts, including administrators, as long as the administrator has the 2FA set up.
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.