The default update settings for a cPanel installation are usually controlled from the WHM interface:
WHM > Server Configuration > Update Preferences
However, there are situations where a greater level of control might be required. In such cases, it is usually easier to modify the update settings right from the command line. The file that needs to be modified is this:
/etc/cpupdate.conf
And it only contains a few options:
CPANEL=release
RPMUP=daily
SARULESUP=daily
STAGING_DIR=/usr/local/cpanel
UPDATES=daily
You can refer to this link from our official documentation, which explains what each line means, what options are available for each line, and what these options do:
Warning:
Please bear in mind that it is strongly recommended to avoid setting the RPMUP and UPDATE options to either never or manual values.
To explain what these two options do; RPMUP determines how to update the operating system’s RPMs, and the UPDATE setting determines how to update cPanel & WHM when updates become available. So these two settings basically keep your system's packages and cPanel updated to the most stable versions, and if these are set to manual (means updates must be applied manually, for example, via the command line) or never (which prevent both automatic and manual updates), then the server would be at the risk of running outdated packages and becomes more vulnerable to many security and performance issues in the long-run.
The recommended value for both of these options is to set both to daily. However, if the daily value is not a possibility, then manual is always preferable to never.