Two vulnerabilities, known as Meltdown and Spectre, have been found affecting almost every Windows desktop and server. Computers affected by these two vulnerabilities are susceptible to having their data stolen, such as personal photos and passwords.
When it comes to security updates, time is usually of the essence. The longer you wait to install a fix from a vendor, the higher the risk of being compromised. But in the cases of the Meltdown and Spectre flaws, you might be better off waiting until a more reliable patch is released.