The CEO of Vupen has announced that his company found their first 0-day exploit for Windows 8. Vupen might not ring a bell as the company doesn't have any consumer products. Instead they sell information and exploits to governments and corporations. This way Vupen's customers can protect themselves, use the exploits to spy on others or use it to create their own mal-ware.
The exploit they found in Windows 8 seems to be be related to Internet Explorer 10 and is now available for sale. This means that Windows 8 users can now be spied on by governments, if required. That's a blow for Microsoft as its latest operating system was considered more secure than previous Windows versions due to the addition of many new security technologies that can be found deep inside the OS.