---
cve: "CVE-2026-42266"
severity: "HIGH"
cvss: 8.8
epss: "63%"
vendor: "jupyterlab"
kev: false
exploited: false
published: "2026-05-13 16:16:47"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-17T20:05:03+02:00"
---

# CVE-2026-42266

> 8.8 HIGH · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- f51404192bf6d0ff79187c884f21e1f91b928146 (Commit)

## Referenzen

- <https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-hwhx-4rc4>
- <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://access.redhat.com/errata/RHSA-2026:43038>
- <https://access.redhat.com/errata/RHSA-2026:60520>
- <https://access.redhat.com/security/cve/CVE-2026-42266>
- <https://bugzilla.redhat.com/show_bug.cgi?id=2477072>
- <https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42266.json>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-42266) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_