Critical vulnerability in Firefox 3.5 and Firefox 3.6
 

Issue:
Mozilla is aware of a critical vulnerability affecting Firefox 3.5 and Firefox 3.6 users. We have received reports from several security research firms that exploit code leveraging this vulnerability has been detected in the wild.

Temporary Solution:
Disabling JavaScript in Firefox
Using the NoScript Add-on

Read more here

Thanks.

Information is very useful.

Firefox vulnerabilities are to be discussed in the dedicated thread. Normally I'd just merge this into it, but being as it's a vulnerability which has already been covered, I'm closing this in order to keep the discussion in one place. That said, thanks for helping to spread the word.