Adobe has issued 2 critcal security patches for Flash Player as well as Adobe Reader and Acrobat. The vulnerability affects Mac, Windows and Linux systems. The vulnerabity allows attackers to take control of the affected computers.
If your Adobe is set to automatic, you will be nagged to death when to install. If your Adobe software isn't set to automatically download updartes, open the program, click HELP --> CHECK FOR UPDATES. Flash users should go to the Adobe Flash page and get the latest version https://get.adobe.com/flashplayer/
You can also manually download the latest patch and read more about the vulnerablity on the Adobe Systems page - http://t.info.adobesystems.com//r/?id=t7a40e0e6,1aa13d24,1b039386 and http://t.info.adobesystems.com//r/?id=t7a40e0e6,1aa13d24,1b039385