Patch Commitpatch
https://github.com/jupyterlab/jupyterlab/commit/4e61e07d0a91145b53fbf96ac74b0387f6bc51f6 CVE-2026-67338
MEDIUM
JupyterLab before 4.5.9 Stored XSS via Extension Manager
Record summary
CVE-2026-67338 has a selected CVSS score of 5.1 (medium).
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.
Description source: CVE List
Exploitation context
CISA SSVC decision
ExploitationNone
AutomatableNo
Technical impactPartial
CISA Coordinator · SSVC 2.0.3 · Evaluated Aug 3, 2026 · Source: CVE List
Affected products and versions
1| Product | Source | Version range | Status |
|---|---|---|---|
jupyterlabBrowse jupyterlab / jupyterlabDefault status: unaffected | CVE List | Before 4.5.9 | affected |
| 4.5.9 | unaffected |
References
5Patch Commitpatch
https://github.com/jupyterlab/jupyterlab/commit/d5d961f6e10a6442dddbf94d9a976b3897055a12 GitHub Security Advisory (GHSA-vmhf-c436-hxj4)Vendor advisory
https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-vmhf-c436-hxj4 nvd.nist.gov
https://nvd.nist.gov/vuln/detail/CVE-2026-67338 VulnCheck Advisory: JupyterLab before 4.5.9 Stored XSS via Extension ManagerThird-party advisory
https://www.vulncheck.com/advisories/jupyterlab-before-stored-xss-via-extension-manager