There aren't any XSS attack vectors via the Apollo Server landing pages known to Apollo, so to our knowledge there is no impact. However, if there are existing XSS vectors that haven't been reported and patched, then all users of Apollo Server's landing pages have a vulnerability which won't be prevented by the current CSP implemented by the landing pages. Prior to version 4.7.1, there was no CSP implemented at all. However, the initial CSP implementation (4.7.1+) reused nonces. While this sufficiently resolved the issue w.r.t. scripts not running in Safari, it did not implement CSP in a safe or conventional way.