About two weeks ago, CentOS Linux 7 and 6 users received kernel and microcode updates that mitigated the Meltdown and Spectre security vulnerabilities unearthed earlier this month. However, after some thorough testing, Red Hat discovered that these updated microcode firmware developed by Intel and AMD caused hardware issues. As a result, Red Hat released on January 17, 2018, another microcode update that reverts to the last known good microcode version released before the one from January 3, 2018. These new updates are now available for CentOS Linux 7 and 6 users as well, and Red Hat strongly recommends users to apply them and install the latest microcode updates from their hardware providers instead.