//-- MyBB 1.10 New XSS ' member.php ' --//

Webattack :-
1- Logout
2- Open Firefox
3- Use [ Live HTTP Headers ]
4- Do Register
5- Agree It
6- Edit Cookies By Live HTTP Headers
7- Add This Cookies
mybb[referrer]="></input><b>HTML</b><input>;

//-- FixIT --//

Open member.php
GoTo Line :- 595 ..


$referrername = $_COOKIE['mybb']['referrer'];


Replace It With

$referrername = htmlspecialchars($_COOKIE['mybb']['referrer']);

//-- --//