cvedb.io
CVE-2026-42557
CRITICAL · CVSS 9.6
EPSS exploitation probability: 0%
Published 2026-05-13T16:16:48.167 · Last modified 2026-06-30T03:19:39.020

Summary

jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. Prior to 4.5.7, JupyterLab's HTML sanitizer allowlists data-commandlinker-command and data-commandlinker-args on button elements, while CommandLinker listens for all click events on document.body and executes the named command without checking whether the element came from trusted JupyterLab UI. A notebook with a pre-saved HTML cell output containing a deceptive button can trigger arbitrary JupyterLab commands - including arbitrary code execution - on a single user click, without any code being submitted for execution by the user. This vulnerability is fixed in 4.5.7.

Affected products

jupyter — jupyterlab

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.