CVE-2026-67338
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.
What this means for your business
- An attacker can use it remotely, over a network, without a login, but only after tricking someone into an action such as opening a file or a link.
- FIRST's prediction model gives it a 0.2% chance of attack attempts being seen in the next 30 days, ranking above 6% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
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Scoring
- CVSS
- 6.1 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N- CVSS v4
- 5.1
- Weakness
- CWE-84
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-08-01
- Last modified
- 2026-09-09
- Sources
- NVD
References
- https://github.com/jupyterlab/jupyterlab/commit/4e61e07d0a91145b53fbf96ac74b0387f6bc51f6
- https://github.com/jupyterlab/jupyterlab/commit/d5d961f6e10a6442dddbf94d9a976b3897055a12
- https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-vmhf-c436-hxj4
- https://www.vulncheck.com/advisories/jupyterlab-before-stored-xss-via-extension-manager