This is a temporary step. There are two versions of their intermediate cert, the one in this article that is cross-signed and another that is signed by their ow

This is a temporary step. There are two versions of their intermediate cert, the one in this article that is cross-signed and another that is signed by their own root (which isn't yet included everywhere). There's a diagram on this page that explains the situation: https://letsencrypt.org/certificates/ https://letsencrypt.org/certificates/