WHM is commonly used by server administrators and hosting resellers. Depending on permissions, it can manage accounts, service settings, installed software and domain-level PHP assignments. It is related to cPanel but serves a different administrative role.
PHP management in WHM may include EasyApache 4, MultiPHP Manager and MultiPHP INI Editor. Those tools can help an administrator choose installed PHP versions and adjust their settings, but a configuration screen alone does not establish that a particular vulnerability has been patched.
WHM installations may use vendor-maintained package streams, including versions with security backports. The exact fixed package build can depend on the operating system, repository and hosting provider.
For a security check, identify the account and domain, find the PHP handler assigned to it, determine the source of that PHP package and verify the update through the corresponding vendor advisory.