PT-2026-59196 · Pypi · Jupyterlab

Published

2026-07-13

·

Updated

2026-07-13

CVSS v4.0

8.4

High

VectorAV:N/AC:L/AT:N/PR:H/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Impact

A stored Cross-Site Scripting (XSS) vulnerability in Jupyter Notebook allows attackers to steal authentication tokens from users who open malicious notebook files and interact with elements that the attacker can make look indistinguishable from legitimate controls (single click interaction).
The vulnerability enables complete account takeover through the Jupyter REST API, allowing the attacker to:
  1. Read all files
  2. Modify/create files
  3. Access running kernels and execute arbitrary code
  4. Create terminals for shell access

Patches

Jupyter Notebook 7.5.6 and JupyterLab 4.5.7 include patches for this vulnerability.

Workarounds

The help extension can be disabled via CLI:
jupyter labextension disable @jupyter-notebook/help-extension
jupyter labextension disable @jupyterlab/help-extension

Hardening

The patched versions include a toggle to disable the command linker functionality altogether, for example via overrides.json:
json
{
 "@jupyterlab/apputils-extension:sanitizer": {
  "allowCommandLinker": false
 }
}

Resources

Acknowledgments

Reported by Daniel Teixeira - NVIDIA AI Red Team

Fix

Found an issue in the description? Have something to add? Feel free to write us 👾

Related Identifiers

PYSEC-2026-2538

Affected Products

Jupyterlab