iOS 4.3.4 Released

Today, Apple released the update to iOS that fixes a PDF vulnerability. The patch closes the security hole that Jailbreakme.com used. Fortunately, no one else was able to come up with an exploit before Apple could patch the security issue.

If you jailbroke your phone, you'll want to hold off on this update, as it could remove your jailbreak, and you'll lose your jailbreak apps and customizations. But, as long as you've installed the PDF patcher from Cydia, you're already protected, so there's no rush.
via AppleInsider