# CVE-2026-73417: JupyterLab arbitrary code execution via malicious overrides.json

Source: https://junglewise.ai/threats/cve-2026-73417-jupyterlab-arbitrary-code-execution-via-malicious-overrides-json  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-13. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-73417 · Severity: medium · CVSS 4 · Published 2026-08-13

JupyterLab is a web-based environment for interactive computing and notebook authoring. A flaw in its settings import feature allows crafted configuration files to execute arbitrary code with the privileges of the user running JupyterLab. An attacker can trick a user into importing a malicious settings file or place one in a shared location, gaining the ability to read, modify, or delete notebooks and run code on connected compute kernels.

Technologies: [Project Jupyter JupyterLab](https://junglewise.ai/threats/technologies/jupyterlab), [jupyterlab (PyPI)](https://junglewise.ai/threats/technologies/pypi-jupyterlab). Vendors: [Project Jupyter](https://junglewise.ai/threats/vendors/project-jupyter), [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-73417 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-73417 being exploited in the wild.

**How severe is CVE-2026-73417?** Medium severity, with a CVSS score of 4, published 13 August 2026.

**Which products and versions are affected?** Project Jupyter JupyterLab 3.3.0 through 4.5.9, 4.6.0 through 4.6.1; jupyterlab (PyPI) ECOSYSTEM:introduced=3.3.0,fixed=4.5.10,introduced=4.6.0,fixed=4.6.2, ECOSYSTEM:introduced=4.6.0,fixed=4.6.2.

**Is there a fix for CVE-2026-73417?** Yes. jupyterlab (PyPI): upgrade to 4.6.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-73417 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-73417?** Check whether you run Project Jupyter JupyterLab or jupyterlab (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- jupyterlab (PyPI): upgrade to 4.6.2 or later

  ```sh
  pip install "jupyterlab>=4.6.2"
  ```


## Technical details

The vulnerability is an unsafe DOM injection in the notebook settings handler, specifically affecting the sideBySideLeftMarginOverride and sideBySideRightMarginOverride settings in packages/notebook-extension/schema/tracker.json and packages/notebook-extension/src/index.ts. These settings are inserted directly into CSS without sanitization, allowing an attacker to inject malicious JavaScript through crafted values in an overrides.json file. Attack vectors include explicit user import via the Settings Editor's Import button, or automatic application of a malicious overrides.json planted in a shared settings location. The embedded code runs with full notebook server access and can execute arbitrary operations. Patches were released in versions 4.5.10 and 4.6.2.

## Affected products

- Project Jupyter JupyterLab 3.3.0 through 4.5.9, 4.6.0 through 4.6.1

## Identifiers

- CVE-2026-73417
- GHSA-pppj-hq3g-57pj
- PYSEC-2026-3672

## Timeline

- 2026-07-21: patched: Security patches released in versions 4.5.10 and 4.6.2
- 2026-08-13: disclosed

## References

- [https://github.com/jupyterlab/jupyterlab/commit/9365f020baec5221deaf11535ed554c06637c999](https://github.com/jupyterlab/jupyterlab/commit/9365f020baec5221deaf11535ed554c06637c999)
- [https://github.com/jupyterlab/jupyterlab/commit/be9303f5bcd5308eaeae953c5a3c903046682c2c](https://github.com/jupyterlab/jupyterlab/commit/be9303f5bcd5308eaeae953c5a3c903046682c2c)

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