🛡️ CVE-2026-40171 on Debian — jupyter-notebook

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

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.

Distribution advisory

This page covers CVE-2026-40171 as tracked by Debian, for the package jupyter-notebook. The fix is available in version 4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-3; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs administrative privileges on the target. A user must actively cooperate. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

Affected software

DEBIAN-CVE-2026-40171 is recorded against 2 packages.

  • jupyter-notebook
  • jupyterlab (fixed in 4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-3)

Timeline and source

Published on 6 May 2026 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

security-tracker.debian.org (Advisory)

CVE-2026-40171 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-05-06
Updated 2026-08-12
Modified 2026-08-04
Fix URL N/A

Affected Packages

Software From version Fixed in
jupyter-notebook — —
jupyterlab — 4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-3

Similar Threats

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