This is a fairly basic "just the security updates, please!" guide for CentOS 6+.

This assumes you're root or have used sudo su.

First, you may need to ensure you have the yum security plugin:

rpm -qa | grep -i yum-plugin-security

If you don't, you can update it with the following.

yum install yum-plugin-security

Now let's check if there are updates:

yum --security check-update

If there are available updates, there will be results after this command.

To update, run the updater with the option --security to specify security updates only.

yum update --security

That's it!

Is something badly out of date? Did this work for you? Please post a comment to help others who might use this for guidance. I originally wrote these instructions around 2013.