🛡️ CVE-2026-42557 on Debian — jupyterlab

⚪ Unknown ✅ No Known Exploit OSV

N/A

CVSS Score

0 Low4 Medium7 High9 Critical10

Description

jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. Prior to 4.5.7, JupyterLab's HTML sanitizer allowlists data-commandlinker-command and data-commandlinker-args on button elements, while CommandLinker listens for all click events on document.body and executes the named command without checking whether the element came from trusted JupyterLab UI. A notebook with a pre-saved HTML cell output containing a deceptive button can trigger arbitrary JupyterLab commands - including arbitrary code execution - on a single user click, without any code being submitted for execution by the user. This vulnerability is fixed in 4.5.7.

Distribution advisory

This page covers CVE-2026-42557 as tracked by Debian, for the package jupyterlab. 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 no privileges on the target. A user must be tricked into taking some action. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality high, integrity high, availability high.

Affected software

DEBIAN-CVE-2026-42557 is recorded against 1 package.

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

Timeline and source

Published on 13 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-2026-42557 on other distributions

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

Base record Ubuntu

Details

Severity Unknown

CVSS Score N/A

CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

CWE N/A

Public Exploit ✅ No

Source OSV

Published 2026-05-13

Updated 2026-08-12

Modified 2026-08-04

Fix URL N/A

Affected Packages

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

References

ADVISORY https://security-tracker.debian.org/tracker/CVE-2026-42557

🔗 NVD 🔗 Mitre

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