All supported versions of Windows, including Windows 10 & Windows RT, will be getting an out-of-band patch to fix a critical zero-day vulnerability. Make sure you check Windows Update for the new patch and get your boxes fixed today! For those that like the manual route, grab the appropriate patch for your OS here.
This security update resolves a vulnerability in Microsoft Windows. The vulnerability could allow remote code execution if a user opens a specially crafted document or visits an untrusted webpage that contains embedded OpenType fonts.