Peer cert cannot be verified or peer cert invalid
First of all we need to ensure that the date and time of the server is correct. Because incorrect date and time will lead to this error on using yum utility.
If the issue persisting even if the date and time are correct, follow the below steps to resolve the error.
Step1: Open the yum configuration file.
Step2: Add or modify the following parameter and save the file.
sslverify=false in /etc/yum.conf
Now yum will work without any issues.