Apologies if this is a rookie question, but I keep wondering what the vulnerabilities section on DockerHub is trying to tell me. Take nextcloud images for instance: The most current images seem to list 3 critical and 22 severe vulnerabilities. Does that mean those vulns are part of the image? If so, why would anyone want to run this?


I mean whatever level of access is required to upload an image. That can be access to the web app (with login), access through WebDAV, or access to the underlying OS or filesystem. If you can put a file on Nextcloud, it is sufficient access.
I forgot to mention that the vulnerability can only be exploited if libraw is also compiled with a particular flag that enables the vulnerable feature. That flag is disabled on base Debian. Docker’s service doesn’t test whether the vulnerability is actually present in the image, only that the package version is listed as affected.