CVE-2026-67338

EUVD-2026-51849
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
6.1 MEDIUM
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 6.87%
Debian logo
Debian Releases
Debian Product
Codename
jupyterlab
forky
4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-5
fixed
sid
4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-6
fixed
trixie
vulnerable
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
jupyterlab
jammy
dne
noble
dne
resolute
needs-triage
Common Weakness Enumeration
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