🛡️ CVE-2026-42266 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. From 4.0.0 to 4.5.6, the allow-list of extensions that can be installed from PyPI Extension Manager (allowed_extensions_uris) is not correctly enforced by JupyterLab. The PyPI Extension Manager was not contained to packages listed on the default PyPI index. This vulnerability is fixed in 4.5.7.

Distribution advisory

This page covers CVE-2026-42266 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 low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

Weakness class

DEBIAN-CVE-2026-42266 is classified as CWE-20: Improper Input Validation. The application accepts input without checking that it has the expected form, so malformed values reach code that assumes they are well formed.

Affected software

DEBIAN-CVE-2026-42266 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-2026-42266 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:3.1/AV:N/AC:L/PR:L/UI:N/S:U/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

Site Security Check

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DEBIAN-CVE-2026-42266 is rated CVSS 8.8 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.

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