Description
JupyterLab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From 4.0.0 to 4.5.6, the allow-list of extensions that can be installed from PyPI Extension Manager (allowed_extensions_uris) is not correctly enforced by JupyterLab. The PyPI Extension Manager was not contained to packages listed on the default PyPI index. This vulnerability is fixed in 4.5.7.
Affected products
jupyter: jupyterlab
References9
- github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-… MitigationVendor Advisory
- github.com/jupyterlab/jupyterlab/releases/tag/v4.5.7 PatchRelease Notes
- jupyterhub.readthedocs.io/en/5.2.1/explanation/websecurity.html Product
- jupyterlab.readthedocs.io/en/latest/user/extensions.html#extens… Product
- access.redhat.com/errata/RHSA-2026:43038
- access.redhat.com/errata/RHSA-2026:60520
- access.redhat.com/security/cve/CVE-2026-42266
- bugzilla.redhat.com/show_bug.cgi?id=2477072
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42266…
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 6% percentile: 93 · as of 14 November 2026
- CWE
- CWE-88CWE-602
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