# CVE-2021-32797: PYSEC-2026-688 - JupyterLab: XSS due to lack of sanitization of the action attribute of an html <form>

Source: https://junglewise.ai/threats/cve-2021-32797-jupyterlab-xss-due-to-lack-of-sanitization-of-the-action  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-02  
License: CC BY 4.0 with a link back

CVE-2021-32797 · Severity: low · CVSS 3.1 · Published 2026-07-02

JupyterLab: XSS due to lack of sanitization of the action attribute of an html <form>

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

## Quick answers

**Is CVE-2021-32797 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-32797 being exploited in the wild.

**How severe is CVE-2021-32797?** Low severity, with a CVSS score of 3.1, published 2 July 2026.

**Which products and versions are affected?** jupyterlab (PyPI) ECOSYSTEM:introduced=0,fixed=1.2.21, GIT:introduced=0,fixed=504825938c0abfa2fb8ff8d529308830a5ae42ed|ECOSYSTEM:introduced=0,fixed=1.2.21,introduced=2,fixed=2.2.10,introduced=2.3,fixed=2.3.2,introduced=3,fixed=3.0.17,introduced=3.1,fixed=3.1.4; notebook (PyPI) ECOSYSTEM:introduced=0,fixed=5.7.11, ECOSYSTEM:introduced=0,fixed=5.7.11,introduced=6.0.0,fixed=6.4.1.

**Is there a fix for CVE-2021-32797?** Yes. jupyterlab (PyPI): upgrade to 1.2.21, 3.1.4 or later; notebook (PyPI): upgrade to 5.7.11, 6.4.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2021-32797?** Check whether you run jupyterlab (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

- jupyterlab (PyPI): upgrade to 1.2.21, 3.1.4 or later

  ```sh
  pip install "jupyterlab>=3.1.4"
  ```

- notebook (PyPI): upgrade to 5.7.11, 6.4.1 or later

  ```sh
  pip install "notebook>=6.4.1"
  ```


## Affected products

- jupyterlab (PyPI) ECOSYSTEM:introduced=0,fixed=1.2.21, GIT:introduced=0,fixed=504825938c0abfa2fb8ff8d529308830a5ae42ed|ECOSYSTEM:introduced=0,fixed=1.2.21,introduced=2,fixed=2.2.10,introduced=2.3,fixed=2.3.2,introduced=3,fixed=3.0.17,introduced=3.1,fixed=3.1.4
- notebook (PyPI) ECOSYSTEM:introduced=0,fixed=5.7.11, ECOSYSTEM:introduced=0,fixed=5.7.11,introduced=6.0.0,fixed=6.4.1

## Identifiers

- CVE-2021-32797
- GHSA-4952-p58q-6crx
- PYSEC-2021-130
- PYSEC-2026-688

## 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 PyPI Extension Manager command injection in uninstall](https://junglewise.ai/threats/cve-2026-102904-jupyterlab-is-an-extensible-environment-for-interactive-and)
- [JupyterLab HTML output sanitization bypass via clipboard paste](https://junglewise.ai/threats/cve-2026-102831-jupyterlab-is-an-extensible-environment-for-interactive-and)
- [JupyterLab code injection via Plural-Forms header in language pack](https://junglewise.ai/threats/cve-2026-102830-jupyterlab-is-an-extensible-environment-for-interactive-and)
- [PYSEC-2026-3671 - JupyterLab: Image viewer allows XSS when opening malicious image in new browser tab](https://junglewise.ai/threats/cve-2026-73415-jupyterlab-image-viewer-allows-xss-when-opening-malicious-image)