RealNetworks has shipped a new version of its RealPlayer software to plug at least four serious security holes in the program. Updates are available for RealPlayer versions 10, 10.5 and 11 for Linux, Mac and Windows systems. Windows versions of RealPlayer are affected by all four vulnerabilities (two of the flaws are once again ActiveX related), while the Linux and Mac versions are exposed to just one of the holes. Regardless, the company is urging all users, regardless of platform, to upgrade their software. To see which version of RealPlayer you’re using, select “Help,” then “About in the program’s menu. Windows users can use the “Check for updates” option. Linux and Mac updates are available here. Regular readers of this blog know that I am not a huge fan of RealPlayer. But there are alternatives. If you just need to hear streaming Real audio, the free and excellent VLC Media