+--------------------------------------------------------------------
+
+ New post Topic Hijacking XSS All vBulletin® v 3.x.x
+
+--------------------------------------------------------------------
+ vendor site........: https://www.vbulletin.com/
+ Affected Software .: vbulletin
+ Class .............: XSS
+ Risk ..............: Low
+ Found by ..........: rUnViRuS
+ Original advisory .: https://www.sec-area.com/
+ Contact ...........: stormhacker[at]hotmail[.]com
+ Vulnerable Script..: showthread.php
+--------------------------------------------------------------------
New Include Redirect Bug XSS [showthread.php] All vBulletin v 3.x.x

This injections would allow an attacker to stealing cookies who be opened url

Xss the page and steal cookie :

xss permanent ( must be post Topic and upload Any File Have Code Xss ) PoC :

<script>alert(document.cookie)</script>.

to be used with cookie stealer following is a simple attack :-
post Topic :-
click on insert link :- 
Hyperlink information
type :- (other)
URl :- ../../xss.txt ( path XSS File On Site[Include Path])


When opened url Will stealing cookies
+--------------------------------------------------------------------
+ [W]orld [D]efacers [T]eam
+ Greets:
+ || rUnViRuS || - || Provide || - || HeX || - || dEv!L RoOT || + || BlackWHITE || - || dOcnok || - || A.tar0uDant.D ||
+ || Pro Hacker || - || DARKFIRE || - || papipsycho ||
+ Sp.Thanx To : Sec-Area.com Member's
+-------------------------[ W D T ]----------------------------------