Is CVE-2026-67338 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-67338?

CVE-2026-67338 has a CVSS v3 severity of MEDIUM (6.1).

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CVE-2026-67338

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.