

The video uses quadlets, which afaik, is just using systemd units to run containers via podman. Therefore, you can just run
podman stop jellyfin (podman ps to get the actual name of the jellyfin container)
podman rm jellyfin
podman pull docker.io/jellyfin/jellyfin:latest
systemctl restart jellyfin.container (or whatever you called your unit when you set it up)
Quick google says you can setup auto updates if you want: https://major.io/p/podman-quadlet-automatic-updates/
Caveat: I am a docker compose user, I may have missed something due to lack of familiarity with quadlets/podman
If that is indeed true it would only mean that the docker container is vulnerable to a supply chain attack. You are not any more vulnerable to a vulnerability in the codebase.
If you’re using the ghcr image, to post malicious code there, the attack would have already had to compromise their github infra … which would likely result in the attacker being able to push malicious code to git or publish malicious releases. Their linux distro packages are self published via a ppa/install script, which I would assume just pull from their github releases, so a bad github release would immediately be pulled as an update by users just as fast as a container.