JupyterLab has an Extension Manager API/GUI Policy Discrepancy allowing 3rd party (malicious) extensions install via POST request.

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-42266
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-05-13 16:16:47 UTC
Updated2026-05-26 18:33:19 UTC
DescriptionJupyterLab 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.

Risk And Classification

Primary CVSS: v3.1 8.8 HIGH from [email protected]

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

EPSS: 0.000290000 probability, percentile 0.089930000 (date 2026-05-29)

Problem Types: CWE-88 | CWE-602 | CWE-88 CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection') | CWE-602 CWE-602: Client-Side Enforcement of Server-Side Security

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary8.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED8.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Jupyter Jupyterlab All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Jupyterlab Jupyterlab affected >= 4.0.0, < 4.5.7 Not specified

References

ReferenceSourceLinkTags
jupyterhub.readthedocs.io/en/5.2.1/explanation/websecurity.html [email protected] jupyterhub.readthedocs.io Product
github.com/jupyterlab/jupyterlab/releases/tag/v4.5.7 [email protected] github.com Patch, Release Notes
jupyterlab.readthedocs.io/en/latest/user/extensions.html [email protected] jupyterlab.readthedocs.io Product
github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-hwhx-4rc4 [email protected] github.com Mitigation, Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
© CVE.report 2026 |

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report