Is CVE-2026-42266 actively exploited?

No active exploitation of CVE-2026-42266 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-42266 be exploited remotely?

Yes. CVE-2026-42266 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-42266?

CVE-2026-42266 has a CVSS score of 8.8 (HIGH).

HOME VULNERABILITIESCVE-2026-42266

HIGH

CVE-2026-42266

CWE-88Published: May 13, 2026· Updated: May 13, 2026

8.8

CVSS v3.1

EPSS:0.06%probability of exploitation in 30 daysPercentile:19.3th

Official 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.

NVD Source

Technical Analysis

CVE-2026-42266 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.8.