CVE-2026-67338

JupyterLab before 4.5.9 Stored XSS via Extension Manager

Published Aug 1, 2026 CVSS 4.0 · 5.1 Medium EPSS < 1% KEV · Not listed
Description
JupyterLab before 4.5.9 contains a stored cross-site scripting vulnerability in the Extension Manager that fails to validate URI protocols in package metadata URLs. Attackers can publish malicious PyPI packages with javascript: URLs in project metadata that execute arbitrary JavaScript in the JupyterLab origin when users click the extension name.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description JupyterLab before 4.5.9 contains a stored cross-site scripting vulnerability in the Extension Manager that fails to validate URI protocols in package metadata URLs. Attackers can publish malicious PyPI packages with javascript: URLs in project metadata that execute arbitrary JavaScript in the JupyterLab origin when users click the extension name.
Title JupyterLab before 4.5.9 Stored XSS via Extension Manager
First Time appeared Jupyter
Jupyter jupyterlab
Weaknesses CWE-84
CPEs cpe:2.3:a:jupyter:jupyterlab:*:*:*:*:*:*:*:*
Vendors & Products Jupyter
Jupyter jupyterlab
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Oct 8, 2026, 3:24 PM
Reserved
Jul 29, 2026, 1:09 PM
Status
Awaiting Analysis
Published
Aug 1, 2026, 1:17 PM
Modified
Oct 8, 2026, 4:17 PM
Severity
Moderate
Public date
Aug 1, 2026, 12:22 PM