No web browser is perfect. Hackers will always find new security holes and opportunities for the media to create press and scare you. What really makes the difference in browser security is the time it takes a company to fix the issues. Within a week of finding out about security related issues in Firefox, the Mozilla team went to work to fix the new found issues.
“A proof of concept of the vulnerabilities was reported last weekend (Mother’s Day weekend) and Mozilla immediately took action to prevent active exploits via changes made to the Mozilla Update web service. We also posted a work around so users can further protect themselves by temporarily disabling automatic install from a web site.
“The Mozilla Foundation is deeply committed to providing a safe and secure Internet experience and staying ahead of potential exploits. The Foundation takes security very seriously and is releasing Firefox 1.0.4 to ensure that we continue to provide users the experience they have come to trust.”
Quote from MozillaZine