Vulnerability in Jupyter Jupyterlab
CVE-2026-42266
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.009 (57.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 57.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.009 · change: +0.002
Affected products
- Jupyter Jupyterlab
- Jupyterlab — versions >= 4.0.0, < 4.5.7
Weakness classification (CWE)
References
- github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-hwhx-4rc4 (Mitigation, Vendor Advisory)
- github.com/jupyterlab/jupyterlab/releases/tag/v4.5.7 (Patch, Release Notes)
- jupyterhub.readthedocs.io/en/5.2.1/explanation/websecurity.html (Product)
- jupyterlab.readthedocs.io/en/latest/user/extensions.html (Product)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-42266?
- CVE-2026-42266 is a high-severity vulnerability in Jupyter Jupyterlab, classified under Argument Injection. CVSS score: 8.8/10. Published 2026-05-13.
- How severe is CVE-2026-42266?
- High severity. CVSS v3 base score is 8.8 out of 10.