Or you can use kernelcare which sideliads kernel patches and not worry about rebooting. This is a commercial product from CloudLinux. We use on all our managed servers just for this reason.
cPanel updates will not update the working kernel version. A yum update is run during updates and a new kernel may be installed but the system must be rebooted into that new kernel in order to use it, unless you use KernelCare or something similar.