For general information see this article https://docs.cpanel.net/knowledge-base/general-systems-administration/how-to-update-your-system/

For the highlights, read the rest of this page.

This information is good for all cPanel servers. Note that in the future, RHEL8 and derived distros move to dnf, however yum should still work as it is usually aliased to dnf.

To update Linux and the kernel, ssh to the server as root or log in via WHM and open the terminal.

Run the command:

dnf update

It will usually ask a yes or no question, answer yes to proceed with update.

While the update is running, DO NOT close the page or tab or it could cause yum database issues.

To update cPanel, log into WHM and open “Upgrade to Latest Version” page. Then click the button to upgrade.

Rebooting the server can be done either from WHM or ssh.

From WHM just open “Graceful Server Reboot” page and click proceed.

From SSH, just run the “reboot” command, no quotes.