On Thursday May 10, CentOS 7.5 (1804) was released. For more information about the release, see the CentOS Project’s Release Notes here: https://wiki.centos.org/Manuals/ReleaseNotes/CentOS7.1804
Before upgrading to CentOS Linux 7.5, it is strongly encouraged to examine the above Release Notes, especially ‘Known Issues’ to see if it may adversely affect your setup;
Included with this release are a large amount of updated packages, including an updated kernel.
To update to CentOS Linux 7.5, run the following commands:
yum clean all
If no update is found, it is possible that your local mirror has not been updated yet or that you may have the CentOS Updates yum repository disabled.