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.
Published: 2026-08-01
Score: 5.1 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Wed, 05 Aug 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-79
References
Metrics threat_severity

None

threat_severity

Moderate


Mon, 03 Aug 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Sat, 01 Aug 2026 12:45:00 +0000

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'}


Subscriptions

Jupyter Jupyterlab
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-03T19:36:40.296Z

Reserved: 2026-07-29T13:09:45.992Z

Link: CVE-2026-67338

cve-icon Vulnrichment

Updated: 2026-08-03T19:36:36.490Z

cve-icon NVD

Status : Received

Published: 2026-08-01T13:17:04.843

Modified: 2026-08-03T20:17:27.450

Link: CVE-2026-67338

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-01T12:22:17Z

Links: CVE-2026-67338 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-05T15:00:05Z

Weaknesses