There are several ways to determine if there is an updated kernel available for the system.
Security Errata; go to the following location for information on security errata, including kernel upgrades that fix security issues:
Via Quarterly Updates; refer to the following location for details:
Use Red Hat Network to download the kernel RPM packages and install the packages. Red Hat Network can download the latest kernel, upgrade the kernel on the system, create an initial RAM disk image if needed, and configure the boot loader to boot the new kernel. For more information, refer to http://www.redhat.com/docs/manuals/RHNetwork/.
If Red Hat Network was used to download and install the updated kernel, following the instructions in Section 39.5 Verifying the Initial RAM Disk Image and Section 39.6 Verifying the Boot Loader, except do not change the kernel to boot by default because Red Hat Network automatically changes the default kernel to the latest version. To install the kernel manually, continue to Section 39.4 Performing the Upgrade.