Microsoft has issued an out-of-band patch update for Windows 10, while other versions of Windows will be patched on Patch Tuesday on January 9, 2018. Apple had already fixed most of these security holes in MacOS 10.13.2 last month. Chrome users can turn on Site Isolation feature on their devices to mitigate these flaws. Microsoft has also released patches by implementing kernel page-table isolation (KPTI) to move the kernel into an entirely separate address space. Android users have to wait for their device manufacturers to release compatible security updates.
Source: https://thehackernews.com/2018/01/meltdown-spectre-vulnerability.html