Vaultvarden - Synology - Cloudflare

I have the following situation:

On a Synology with Container Station, I have installed Vaultwarden. In the Container Station, I have set up port forwarding from port 80 via the Web Station to the alias “Vault.”

The Synology itself and all its services (Photo, Video, etc.) are accessible without any problems. The internet domain is routed through a Cloudflare tunnel (Zerotrust).

The service is accessible via the local LAN URL (, but it is not accessible via the internet domain

It just displays the classic “Site cannot be found” error from the Synology Web Station.

Someone else with a similar construction?

I have the same setup.
You need to configure a public hostname on cloudflare (zero trust - networks - tunnels) for your vaultwarden. Choose http as the service and your local synology ip (including vaultwarden port) as the url.