Meltdown and Spectre exploit critical vulnerabilities in all modern processors that allows a rogue process to read any physical, kernel or other process’s mapped memory, regardless of whether or not it should be able to do so.
As it turns out this is not as big of a deal as it has been reported. To use the exploit turns out to be a bit more difficult than the reports are saying. You should be able to avoid this issue by keeping your software up to date
Microsoft and other software venders have rendered patches or will render patches for to fix these vulnerabilities.