CVE-2025-23205 `frame-ancestors: self` grants all users access to formgrader in nbgrader

nbgrader is a system for assigning and grading notebooks. Enabling frame-ancestors: 'self' grants any JupyterHub user the ability to extract formgrader content by sending malicious links to users with access to formgrader, at least when using the default JupyterHub configuration of enablesubdomai...