The latest update to Firefox addresses 67 bugs and enhancements, according to Mozilla. 23 bugs were marked as "critical" or higher. These numbers are slightly inflated because they contain the ones already fixed in the 3.0.8 emergency update on March 27th.
Nine potential security vulnerabilities were patched including 2 marked as "high" and 1 "critical":
The security issues were reported by Olli Pettay, Martijn Wargers, Mats Palmgren, Oleg Romashin, Jesse Ruderman, Gary Kwong, Igor Bukanov, Bob Clary, Gregory Fleischer, Daniel Veditz, Moxie Marlinspike, Cefn Hoile, Prateek Saxena, and Paolo Amadini. Mozilla has been updating Firefox 3 approximately once a month since its release in June of last year. Here's a list of all the updates so far: