Secunia has sent out a couple of advisories (here and here) for the Sun Java runtime (including early versions) that you install on your Windows, Solaris, or Linux computer, for the Web Start, and for the Java Development Kit or the Software Development Kit.
The vulnerabilities are rated highly critical and allow system access from a remote location. You should go to the Sun Java pages (here, here and here) and download and install the latest version of the software you are using.
Computer users often have the runtime installed and should download the update(s) here, here, or here.
It’s possible in Windows to have more than one version of the runtime installed – you should update all versions that you have installed on your computer. Look in Control Panel / Add/Remove programs to see what version you have to find out which update(s) to download. You can also try this Web page or open a command prompt (Start / Run / type cmd – command for Windows ME and earlier – and click OK) and type “java -version” (without the quotes) and press Enter. The result will look something like this:
java version “1.4.2_06”
Java 2 Runtime Environment, Standard Edition (build 1.4.2_06-b03)
Java HotSpot Client VM (build 1.4.2_06-b03, mixed mode)