Impact

Users of JupyterHub deployments running DockerSpawner starting with 0.11.0 without specifying DockerSpawner.allowedimages configuration allow users to launch any pullable image, instead of restricting to only the single configured image, as intended.

Patches

Upgrade to DockerSpawner 13.

Workarounds

Explicitly setting DockerSpawner.allowedimages to a non-empty list containing only the default image will result in the intended default behavior:

python c.DockerSpawner.image = "your-image" c.DockerSpawner.allowedimages = ["your-image"]