http://www.pcgamer.com/serious-intel-cpu-design-flaw-may-require-a-windows-patch-but-probably-wont-affect-gaming-performance/

A report on LWN, a Linux kernel development site (sub required), details of a hardware bug in modern Intel CPUs that allows an attacker to access low-level kernel memory that is normally protected from higher level (programs and user) access. As reported on The Register, this bug could have big consequences, requiring OS kernel patches on Windows, Linux, and OS X. Those fixes could actually cause the affected CPUs to perform more slowly, but don't panic: your gaming PC is unlikely going to see a dramatic change as a result.

This is complicated stuff, so I'll try to break it down. The method of attack revolves around identifying virtual memory pages in specific sequences that reveal locations in memory where protected kernel space resides. The bug is a hardware bug, so there's no easy fix except to wait for AMD and Intel to implement a fix in next generation CPUs. The flaw affects multiple generations of Intel CPUs.