Apple has updated Safari to version 4.0.3, reportedly fixing some stability and compatibility issues but also, plugging a number of security holes.  Two of the security patches apply to the version of Apple's browser that runs on Microsoft's operating system. If yiou have Safari installed, it is important that you apply these security patches detailed in a security advisory on Apple's website.  Affected users can either retrieve the update to Safari via Apple's Software Update feature, or download it directly from Apple's website.

The vulnerabilities include a fix for Safari promoting malicious websites on its at-a-glance "Top Sites" view, unwanted data leakage, and an exploit that could be used by hackers to run malicious code on your computer.