A new vulnerability in Vbulletin 4.x.x and 5.x.x has been identified, which if exploited would apparently give hackers complete and total control over your forums.
See this article for details:
http://news.softpedia.com/news/vBull…t-401051.shtml
Furthermore, Vbulletin’s support forums were hacked and they are asking people to reset their passwords.
