AIKIDO-2026-835649

TL;DR

marimo merges configuration taken from a notebook's PEP-723 inline script metadata into the running session with higher precedence than the operator's own settings. The pyproject sanitizer does not sufficiently restrict which fields a notebook may set, so a notebook author can inject a custom AI base URL. When the operator opens the crafted notebook and makes an AI request, marimo sends the request to the notebook-controlled endpoint while authenticating with the operator's configured API key, leaking that key without any cell execution. The fix tightens sanitization so untrusted notebook metadata can no longer override sensitive connection settings.