CVE-2026-42266
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-42266
Vendor advisory: security-advisories@github.com — https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-hwhx-4rc4
Vendor advisory: security-advisories@github.com — https://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.7
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| debian | forky | affected | |
| debian | sid | affected | |
| debian | trixie | affected | |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| PyPI | jupyterlab | >=4.0.0,<4.5.7 | 4.5.7 |
| PIP | jupyterlab | >= 4.0.0, <= 4.5.6 | 4.5.7 |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| jupyter | jupyterlab | {"startIncluding":"4.0.0","endExcluding":"4.5.7"} | 4.5.7 |
References
- https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-hwhx-4rc4
- https://nvd.nist.gov/vuln/detail/CVE-2026-42266
- https://github.com/jupyterlab/jupyterlab
- https://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.7
- https://jupyterhub.readthedocs.io/en/5.2.1/explanation/websecurity.html
- https://jupyterlab.readthedocs.io/en/latest/user/extensions.html#extension-manager-implementations
- https://security-tracker.debian.org/tracker/CVE-2026-42266
- https://github.com/advisories/GHSA-37w4-hwhx-4rc4
CWEs
CWE-88 CWE-602
Verify integrity in audit chain (admin only). AS-IS.