CentOS has discontinued support for version 6 of its operating systems as of November 30, 2020.
CentOS - End of Lifetime (EOL) Dates
What is the support ''end of life'' for each CentOS release?
To ensure compatibility with the latest versions of cPanel & WHM, please update your server to an x86_64 system with CentOS 7 or above.
CloudLinux OS 6 Support extended to 2024
CentOS 6 will reach the end of life in November of 2020, which means no more security patches or bug fixes. To help customers who are currently using cPanel & WHM on a CentOS 6 server, we have teamed up with the CloudLinux team to extend the life of CloudLinux OS 6. Anyone hoping to delay the inevitable migration can purchase a CloudLinux license and install the hybrid kernel provided by CloudLinux. You’ll also be able to take advantage of all of the additional benefits of CloudLinux.
cPanel & WHM Version 86: The last version to support CentOS 6
cPanel & WHM version 11.86 is the last version available for CentOS 6. This version reached EOL in November 2020. More details regarding cPanel's EOL and LTS Support can be found here:
CentOS 6 EOL, CloudLinux 6 OS, and you!
As CentOS version 6 has reached its End of Life, all official repositories have been removed, while most mirrors are updating to remove these as well. This prevents yum updates and other package management from functioning as required.
Workaround
An autofixer, which updates the repository mirrors to utilize the ones from vault.centos.org, has been implemented. The next cPanel / WHM update will automatically apply the autofixer.
To run the autofixer you can do so with the following command:
# /scripts/autorepair centos6_base_repo_is_no_more
If a modified repository file exists, our autofixer will not enable the vault repository.
For additional information on how to manually enable the vault repository please review the following article.
How to manually fix the base repository on EOL CentOS 6 to enable package installation via yum