Comment by amiga386

There's nothing wrong with exposing it to the internet.

There have been exploits: https://github.com/jellyfin/jellyfin/security

The project is a fork of another project (Emby) and there has always been potential for user-supplied data ending up in command-line arguments, or exploitation of the (admin) user getting to upload various files. Nonetheless, all reported security bugs have been fixed promptly, and they're proactively sweeping through the full set of APIs they inherited, looking for possible exploit paths.

Most exploits required an authenticated user.

If you're concerned about this, you should run Jellyfin's docker image, with read-only mounts of your media library, and only give accounts to people you trust, which is how you should treat your personal media library anyway.