Intel

AIKIDO-2026-811821

jupyterlab is vulnerable to Cross-Site Scripting (XSS)

Cross-Site Scripting (XSS)CVE-2026-67338 Published Yesterday

61

Medium Risk

This Affects:

PYTHONjupyterlab
0.34.0 - 4.5.8
Fixed in 4.5.9
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TL;DR

The JupyterLab Extension Manager renders a package's home-page link from PyPI project metadata without validating the URI protocol. A package published with a javascript: URL in its metadata is copied into the frontend link and stored, so viewing the extension listing and clicking the extension name runs the embedded script in the JupyterLab origin. This stored cross-site scripting can be escalated to code execution through the notebook server and connected kernels. The fix validates and neutralizes non-safe URI protocols before the link is rendered.

Who does this affect?

You are affected if you run an affected jupyterlab version with the Extension Manager enabled against the default PyPI source, and you open the extension listing and click the name of an untrusted package whose PyPI project metadata carries a javascript: home-page URL.

Background info

jupyterlab is vulnerable to Cross-Site Scripting (XSS) in versions 0.34.0 - 4.5.8.

How to fix this

Upgrade the jupyterlab library to the patch version.