# CVE-2019-9644: PYSEC-2026-2531 - Improper Neutralization of Input During Web Page Generation in Jupyter Notebook

Source: https://junglewise.ai/threats/cve-2019-9644-improper-neutralization-of-input-during-web-page-generation-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-09  
License: CC BY 4.0 with a link back

CVE-2019-9644 · Severity: low · CVSS 3 · Published 2026-07-09

Improper Neutralization of Input During Web Page Generation in Jupyter Notebook

Technologies: [notebook (PyPI)](https://junglewise.ai/threats/technologies/pypi-notebook). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2019-9644 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2019-9644 being exploited in the wild.

**How severe is CVE-2019-9644?** Low severity, with a CVSS score of 3, published 9 July 2026.

**Which products and versions are affected?** jupyter-notebook (PyPI) ECOSYSTEM:introduced=0,fixed=5.7.6; notebook (PyPI) ECOSYSTEM:introduced=0,fixed=5.7.6.

**Is there a fix for CVE-2019-9644?** Yes. jupyter-notebook (PyPI): upgrade to 5.7.6 or later; notebook (PyPI): upgrade to 5.7.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2019-9644?** Check whether you run jupyter-notebook (PyPI) or notebook (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

- jupyter-notebook (PyPI): upgrade to 5.7.6 or later

  ```sh
  pip install "jupyter-notebook>=5.7.6"
  ```

- notebook (PyPI): upgrade to 5.7.6 or later

  ```sh
  pip install "notebook>=5.7.6"
  ```


## Affected products

- jupyter-notebook (PyPI) ECOSYSTEM:introduced=0,fixed=5.7.6
- notebook (PyPI) ECOSYSTEM:introduced=0,fixed=5.7.6

## Identifiers

- CVE-2019-9644
- GHSA-hhx8-cr55-qcxx
- PYSEC-2019-159
- PYSEC-2026-2531

## Related threats

- [JupyterLab command link trust prompt marks wrong document](https://junglewise.ai/threats/cve-2026-102832-jupyterlab-command-link-trust-prompt-in-jupyterlab-can-trust-a)
- [JupyterLab HTML output sanitization bypass via clipboard paste](https://junglewise.ai/threats/cve-2026-102831-jupyterlab-is-an-extensible-environment-for-interactive-and)
- [PYSEC-2026-2536 - HTML injection in Jupyter Notebook and JupyterLab leading to DOM Clobbering](https://junglewise.ai/threats/cve-2024-43805-html-injection-in-jupyter-notebook-and-jupyterlab-leading-to-dom)
- [PYSEC-2026-2534 - JupyterLab vulnerable to potential authentication and CSRF tokens leak](https://junglewise.ai/threats/cve-2024-22421-jupyterlab-vulnerable-to-potential-authentication-and-csrf-tokens)
- [PYSEC-2026-2535 - JupyterLab vulnerable to SXSS in Markdown Preview](https://junglewise.ai/threats/cve-2024-22420-jupyterlab-vulnerable-to-sxss-in-markdown-preview)