Updating glibc on Red Hat Linux or CentOS Linux is a very simple process. Most commonly you will use the following command in the case of a security vulnerability, or perhaps just to verify that you’re running the most up-to-date library:
yum -y update glibc
In this case, yum is the rpm-based package manager for both Red Hat and CentOS, -y, –assumeyes gives yes as an answer to any question which would be asked by running the command, update is for updating the package, and glibcis the package you’re updating!
Assuming your server needed a new version of glibc and was thus upgraded, reboot your server to complete the process!