Cloudflare allows traffic for the default cPanel ports, 2082 (HTTP) and 2083 (HTTPS). 

To access your cPanel with Cloudflare enabled, try any of the following:

• example.com:2082/
• example.com:2083/ (over SSL)
• example.com/cpanel (often a redirect to one of the above)

If you want to access cPanel without going through Cloudflare, try one of the following

• cpanel.example.com (if you’ve set up that DNS record)