CVE catalog

CVE-2026-40171

Severity: High · CVSS 8.8CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Published: Apr 30, 2026, 5:25:47 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.48% · Oct 25, 2026

In Jupyter Notebook versions 7.0.0 through 7.5.5, JupyterLab versions 4.5.6 and earlier, and the corresponding @jupyter-notebook/help-extension and @jupyterlab/help-extension packages before 7.5.6 and 4.5.7, a stored cross-site scripting issue in the help command linker can be chained with attacker-controlled notebook content to steal authentication tokens with a single click. An attacker can craft a malicious notebook file containing elements that appear indistinguishable from legitimate controls and trigger execution when a user interacts with them. Successful exploitation allows theft of the user's authentication token and complete takeover of the Jupyter session through the REST API, including reading files, creating or modifying files, accessing kernels to execute arbitrary code, and creating terminals for shell access. This issue has been fixed in Notebook 7.5.6, JupyterLab 4.5.7, @jupyter-notebook/help-extension 7.5.6, and @jupyterlab/help-extension 4.5.7. As a workaround, disable the affected help extensions or set allowCommandLinker to false in the sanitizer configuration.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	jupyter-notebook	sid	`7.4.7-3`	fixed
Debian	jupyter-notebook	forky	`7.4.7-3`	fixed
Debian	jupyter-notebook	trixie	`6.4.13-5`	not affected
Debian	jupyter-notebook	bookworm	`6.4.12-2.2`	not affected
Npm	@jupyter-notebook/help-extension	Not reported	`7.5.6`	fixed
PyPI	notebook	Not reported	`7.5.6`	fixed
PyPI	jupyterlab	Not reported	`4.5.7`	fixed
Npm	@jupyterlab/help-extension	Not reported	`4.5.7`	fixed
PyPI	jupyterlab	Not reported	`4.5.7`	fixed
Opensuse	python-notebook	tumbleweed	`7.5.6-1.1`	fixed
Opensuse	python-jupyterlab	tumbleweed	`4.5.7-1.1`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	jupyter-notebook	source	sid	`7.4.7-3`	not yet assigned	Not reported	Not reported
Debian	jupyter-notebook	source	forky	`7.4.7-3`	not yet assigned	Not reported	Not reported
Debian	jupyter-notebook	source	trixie	`Not affected`	unimportant	Not reported	Not reported
Debian	jupyter-notebook	source	bookworm	`Not affected`	unimportant	Not reported	Not reported
Npm	@jupyter-notebook/help-extension	npm	Not reported	`7.5.6`	Not reported	GHSA-RCH3-82JR-F9W9	Not reported
PyPI	notebook	PyPI	Not reported	`7.5.6`	Not reported	GHSA-RCH3-82JR-F9W9	Not reported
PyPI	jupyterlab	PyPI	Not reported	`4.5.7`	Not reported	GHSA-RCH3-82JR-F9W9	Not reported
Npm	@jupyterlab/help-extension	npm	Not reported	`4.5.7`	Not reported	GHSA-RCH3-82JR-F9W9	Not reported
PyPI	jupyterlab	PyPI	Not reported	`4.5.7`	Not reported	PYSEC-2026-2538	Not reported
Opensuse	python-notebook	rpm	tumbleweed	`7.5.6-1.1`	Not reported	OPENSUSE-SU-2026:10749-1	Not reported
Opensuse	python-jupyterlab	rpm	tumbleweed	`4.5.7-1.1`	Not reported	OPENSUSE-SU-2026:10748-1	Not reported

OpenFactory catalog packages

[Debian 13 (Trixie)]

[jupyterlab]Affected
Details (2)
- 4.0.11+ds1+~cs11.25.27-7 · all · trixie
  Affected
  nvd · jupyterlab · debian · 13
- 4.0.11+ds1+~cs11.25.27-7 · all · trixie
  Affected
  nvd · jupyterlab · debian · 13

[openSUSE Tumbleweed]

[jupyter-jupyterlab]Unknown
Source package: [python-jupyterlab]
Details (1)
- 4.5.10-1.1 · noarch · tumbleweed
  Unknown · Fixed: 4.5.7-1.1
  Version impact unknown
  nvd · python-jupyterlab · opensuse · tumbleweed
[jupyter-notebook]Unknown
Source package: [python-notebook]
Details (1)
- 7.5.6-1.3 · noarch · tumbleweed
  Unknown · Fixed: 7.5.6-1.1
  Version impact unknown
  nvd · python-notebook · opensuse · tumbleweed
[python313-jupyterlab]Unknown
Source package: [python-jupyterlab]
Details (1)
- 4.5.10-1.1 · noarch · tumbleweed
  Unknown · Fixed: 4.5.7-1.1
  Version impact unknown
  nvd · python-jupyterlab · opensuse · tumbleweed
[python313-notebook]Unknown
Source package: [python-notebook]
Details (1)
- 7.5.6-1.3 · noarch · tumbleweed
  Unknown · Fixed: 7.5.6-1.1
  Version impact unknown
  nvd · python-notebook · opensuse · tumbleweed
[python314-jupyterlab]Unknown
Source package: [python-jupyterlab]
Details (1)
- 4.5.10-1.1 · noarch · tumbleweed
  Unknown · Fixed: 4.5.7-1.1
  Version impact unknown
  nvd · python-jupyterlab · opensuse · tumbleweed
[python314-notebook]Unknown
Source package: [python-notebook]
Details (1)
- 7.5.6-1.3 · noarch · tumbleweed
  Unknown · Fixed: 7.5.6-1.1
  Version impact unknown
  nvd · python-notebook · opensuse · tumbleweed

[Debian 12 (Bookworm)]

[jupyter-notebook]Not affected
Details (2)
- 6.4.12-2.2 · all · bookworm
  Not affected
  nvd · jupyter-notebook · debian · bookworm
- 6.4.12-2.2 · all · bookworm
  Not affected
  nvd · jupyter-notebook · debian · bookworm
[python3-notebook]Not affected
Source package: [jupyter-notebook]
Details (2)
- 6.4.12-2.2 · all · bookworm
  Not affected
  nvd · jupyter-notebook · debian · bookworm
- 6.4.12-2.2 · all · bookworm
  Not affected
  nvd · jupyter-notebook · debian · bookworm
[python-notebook-doc]Not affected
Source package: [jupyter-notebook]
Details (2)
- 6.4.12-2.2 · all · bookworm
  Not affected
  nvd · jupyter-notebook · debian · bookworm
- 6.4.12-2.2 · all · bookworm
  Not affected
  nvd · jupyter-notebook · debian · bookworm

Observed: Oct 23, 2026, 10:25:55 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]