It's possible to define the Content Security Policy with a <META> tag in the "bootstrap page" and prevent this kind of security issue, e.g. <META http-equiv="content-security-policy" content="connect-src 'self' data: blob:;">
But the whole reason for CSP was to allow us to use external libraries without exfiltration risk. If we stop using external libraries, then our motivation for using CSP is gone. So CSP is useless for the purpose of this conversation.