CVE-2026-67338

JupyterLab before 4.5.9 contains a stored cross-site scripting vulnerability in the Extension Manager that fails to validate URI protocols in package metadata URLs. Attackers can publish malicious PyPI packages with javascript: URLs in project metadata that execute arbitrary JavaScript in the...

JupyterLab: PyPI extension blocklist package-name canonicalization bypass

JupyterLab's PyPI extension manager enforces blockedextensionsuris by comparing the requested install name to blocklist entries with a custom string normalization that is weaker than PyPI package-name canonicalization. An authenticated user can request a PyPI-equivalent spelling such as...

CVE-2026-42266 JupyterLab has an Extension Manager API/GUI Policy Discrepancy allowing 3rd party (malicious) extensions install via POST request.

JupyterLab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From 4.0.0 to 4.5.6, the allow-list of extensions that can be installed from PyPI Extension Manager allowedextensionsuris is not correctly enforced by JupyterLab. The Py...