VulnerabilityAwaiting Analysis
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.
MEDIUM 5.1EPSS 0.17%
Does this matter?
Lower severity and a low EPSS score (0.17%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 5.1 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.17% probability · 7th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-84
- Source
- disclosure@vulncheck.com
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.