If you normally only check for updates on Patch Tuesdays, break that habit and run windows update as soon as possible. CVE-2015-2426 is fixed by the Microsoft update KB3079904, or KB3074667 for Windows 10.
The exploit is found on every version of Windows even up to not yet commercially released Windows 10. The vulnerability is in the adobe type manager library, and can allow any infected or malicious website to gain full control of computers who visit them.
All versions of Windows from vista and up can get this patch directly from Windows Update.
If you’re still running Windows XP get your head out of your ass and upgrade.