Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
Medium, CVSS 6.3amended

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

CVE-2021-32797GHSA-4952-p58q-6crx

What to do

Vendor fix available. Upgrade each affected package to the fixed version on its release line (jupyterlab 3.1.4, 3.0.17, 2.3.2, 2.2.10, 1.2.21; notebook 6.4.1, 5.7.11), redeploy, then verify what is actually installed.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

  • PyPI jupyterlab

    Affected
    < 1.2.21>= 2.0.0a0, < 2.2.10>= 2.3.0a0, < 2.3.2>= 3.0.0a0, < 3.0.17>= 3.1.0a0, < 3.1.4
    Fixed in
    3.0.17, 2.2.10, 1.2.21, 3.1.4, 2.3.2

  • PyPI notebook

    Affected
    < 5.7.11>= 6.0.0, < 6.4.1
    Fixed in
    6.4.1, 5.7.11

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS 4.0
6.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N · score source
EPSS
  • CVE-2021-32797: 2.66% estimated exploitation activity in the next 30 days; percentile 85.71 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

Impact Untrusted notebook can execute code on load. This is a remote code execution, but requires user action to open a notebook. Patches Patched in the following versions: 3.1.4, 3.0.17, 2.3.2, 2.2.10, 1.2.21. References OWASP Page on Restricting Form Submissions For more information If you have any questions or comments about this advisory, or vulnerabilities to report, please email our security list security@ipython.org. Credit: Guillaume Jeanne from Google

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 3 · amended ·

    Amended from ghsa record GHSA-4952-p58q-6crx

  2. Revision 2 · amended ·

    Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

  3. Revision 1 · created ·

    Published from osv record GHSA-4952-p58q-6crx

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2021-32797

Advisory: JupyterLab: XSS due to lack of sanitization of the action attribute of an html
IDs: CVE-2021-32797, GHSA-4952-p58q-6crx
Record: https://patchnext.com/advisories/cve-2021-32797 (revision 3, source checked 26 Oct 2026, 13:26 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: jupyterlab 3.1.4, 3.0.17, 2.3.2, 2.2.10, 1.2.21; notebook 6.4.1, 5.7.11. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI jupyterlab: affected < 1.2.21; >= 2.0.0a0, < 2.2.10; >= 2.3.0a0, < 2.3.2; >= 3.0.0a0, < 3.0.17; >= 3.1.0a0, < 3.1.4; fixed in 3.0.17, 2.2.10, 1.2.21, 3.1.4, 2.3.2
- PyPI notebook: affected < 5.7.11; >= 6.0.0, < 6.4.1; fixed in 6.4.1, 5.7.11

## Suggested inspection (read-only)
- `python -m pip show jupyterlab`: prints the installed version. Run with the environment that serves production active.
- `python -m pip show notebook`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on jupyterlab, notebook.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-4952-p58q-6crx (OSV record GHSA-4952-p58q-6crx lists affected ranges: PyPI jupyterlab >=0 =2.0.0a0 =2.3.0a0 =3.0.0a0 =3.1.0a0 =0 =6.0.0 <6.4.1 (fixed))
- Verified: https://github.com/advisories/GHSA-4952-p58q-6crx (GitHub-reviewed advisory GHSA-4952-p58q-6crx lists affected ranges: PyPI jupyterlab >=0 =2.0.0a0 =2.3.0a0 =3.0.0a0 =3.1.0a0 =0 =6.0.0 <6.4.1)

Commands are suggestions: review each one before running it.

Loading voting…