To check and apply only security updates using the yum package manager on a Red Hat or CentOS Linux system, you can use the update-minimal command and the --security option.
For example, to check for and apply only security updates, you can use the following command:
yum update-minimal --security
This will check for available security updates and install them, if any are found.
You can also use the --security-severity option to specify the severity level of the security updates to apply. For example, to apply only critical security updates, you can use the following command:
yum update-minimal --security --security-severity=Critical
It's always a good idea to carefully review the documentation and use the appropriate options to ensure that you are applying the correct updates to your system.