Spectre and Meltdown are the names of security vulnerabilities found in many processors from Intel, ARM and AMD that could allow attackers to steal your passwords, encryption keys and other private information. The issues apply to all modern processors and affect nearly all operating systems (Windows, Linux, Android, iOS, macOS, and more), smartphones and other computing devices made in the past 20 years. Microsoft has already released an out-of-band security update for Windows 10 to address the Meltdown issue and will be releasing patches for Windows 7 and Windows 8 on January 9th.
Source: https://thehackernews.com/2018/01/meltdown-spectre-patches.html