Certificates issued by Let's Encrypt are cross-signed by IdenTrust and are trusted by all major browsers[1]. This is just about their own root certificate. Bein

Certificates issued by Let's Encrypt are cross-signed by IdenTrust and are trusted by all major browsers[1]. This is just about their own root certificate. Being cross-signed by an existing, trusted CA is a common practice for new CAs, as it would take years for the CA to become usable in practice otherwise. [1]: https://community.letsencrypt.org/t/which-browsers-and-operating-systems-support-lets-encrypt/4394 https://community.letsencrypt.org/t/which-browsers-and-opera...