WordPress TheCartPress 1.5.3.6 contains an unauthenticated privilege escalation vulnerability that allows attackers to create administrator accounts by submitting crafted requests to the AJAX handler. Attackers can send POST requests to the tcp_register_and_login_ajax action with tcp_role set to administrator to gain full administrative access without authentication.
https://www.vulncheck.com/advisories/wordpress-thecartpress-privilege-escalation-unauthenticated