Fedora Magazine - https://fedoramagazine.org/protect-fedora-system-meltdown/
You may have heard about Meltdown, an exploit that can be used against modern processors (CPUs) to maliciously gain access to sensitive data in memory. This vulnerability is serious, and can expose your secret data such as passwords. Here’s how to protect your Fedora system against the attack.
Guarding against Meltdown
New kernel packages contain fixes for Fedora 26 and 27 (kernel version 4.14.11), as well as Rawhide (kernel 4.15 release candidate). The maintainers have submitted updates to the stable repos. They should show up within a day or so for most users.
To update your Fedora system, use this command once you configure sudo.