We highly recommend enabling automatic security updates to your server instances to ensure they are always patched with fixes for the latest security vulnerabilities. 

If you would like to enable this for your instances, depending on your Linux distribution, this may differ.

CentOS Linux 7

CentOS 7 and earlier use the yum-cron package for applying automatic upgrades with the YUM package manager. We found the HowtoForge guide for how to set up Automatic Security Updates on CentOS 7 to be a good reference. 

CentOS Linux 8 or later and Fedora Linux

CentOS 8 and Fedora Linux use the dnf-automatic package for automatic upgrades with the DNF package manager. Again, we found the HowtoForge guide for Automatic Package Updates on CentOS 8 to be a good reference, which also applies to Fedora Linux.

Debian and Ubuntu Linux

Debian and Ubuntu use the APT package manager which can apply automatic updates via the unattended-upgrades package. See the Debian Wiki page on Unattended Upgrades or Ubuntu's Documentation on enabling Automatic Security Upgrades