The Ferron 3 Docker image that smtp-01.hosts.ferron.sh relies on is now based on Ferron 3.0.0-rc.2, and we updated that and that fixed the incident as a whole. Thank you for your patience.

Internal build of Ferron 3.0.0-rc.2 codebase has been deployed into internal staging Docker image, resolving the incident in web-01.hosts.ferron.sh. smtp-01.hosts.ferron.sh is still affected, as it uses a public Ferron 3 Docker image, which still has the version with critical bug.

The incident happened, because of a critical HTTP/2 bug in Ferron 3.0.0-rc.1. Emergency bugfix of Ferron 3.0.0-rc.2 is compiling.