When installing SharePoint Framework solutions, SharePoint shows you the URLs of external scripts used by the solution. But it doesn't show all of them, so be careful what solutions you allow to run unrestricted in your tenant.
Many articles about building SharePoint Framework solutions mention uploading your files to a CDN. But are you sure you actually need one? What is a CDN Content Delivery Network (CDN) is a system, that uses servers distributed around the globe to deliver files to users. By automatically choosing the server