@neko The issue seems to be with a singular CA with jury-rigged ACME server and is fixed at least the base script. That CA immediately closed down after that for some reason. Can't say if it can't be exploited with dozens of hooks for DNS hosters, though.
I guess the only redeeming detail is that hopefully CAs are trustworthy so hopefully none of them would take advantage of this RCE vuln so hopefully no actual exploits happened in practice