Red Hat Security Advisory 2018-0021-01 - The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements. Security Fix: An industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of instructions. There are three primary variants of the issue which differ in the way the speculative execution can be exploited. Note: This issue is present in hardware and cannot be fully fixed via software update. The updated kernel packages provide software mitigation for this hardware issue at a cost of potential performance penalty. Please refer to References section for further information about this issue and the performance impact.