XSS vulnerability found in RankMyHack.com

A Hacker Named as "lolstorm" found a XSS vulnerability in Rankmyhack.com. The contact form of the website is vulnerable to XSS(cross site scripting). RankmyHack is a hackers ranking site based on their hack.

Vulnerable Link:
www.rankmyhack.com/contact.php

POC:
www.rankmyhack.com/contact.php?subject=XSS onmouseover=alert(this.value);

This displays an alert box with "XSS".