A vulnerability in a Java plug-in from Sun Microsystems used by most web browsers poses a risk for users of IE and alternative browsers alike. Because of the flaw, malicious applets can escape the safe confines of a sandbox and damage vulnerable systems.
Java Runtime version 1.4.2_05 and older are vulnerable. According to Finnish security researcher Jouko Pynnonen, who discovered the problem, the risk is not limited to IE users but also affects Mozilla Firefox both on Windows and Linux systems. Opera users also at risk.
Similar vulnerabilities have been widely exploited by malicous websites in the past. Users are advised to update their Java software, no matter which operating system you are using. Updated versions can be found here. ®