CVE-2026-42557
Fixed in a distro release EPSS <1%CVSS 8.6
jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. Prior to 4.5.7, JupyterLab's HTML sanitizer allowlists data-commandlinker-command and data-commandlinker-args on button elements, while CommandLinker listens for all click events on document.body and executes the named command without checking whether the element came from trusted JupyterLab UI. A notebook with a pre-saved HTML cell output containing a deceptive button can trigger arbitrary JupyterLab commands - including arbitrary code execution - on a single user click, without any code being submitted for execution by the user. This vulnerability is fixed in 4.5.7.
Products: jupyterlab, jupyter notebook, Red Hat Migration Toolkit for Applications 8.2, Red Hat OpenShift AI 3.4, Red Hat OpenShift AI (RHOAI)
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| PyPI | jupyterlab | 4.5.7 |
| PyPI | notebook | 7.5.6 |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Chainguard | datahub-ingestion-fips | 1.5.0.1-r2 |
| Debian 13 | jupyterlab | no fix |
| Debian 14 | jupyterlab | 4.4.10+ds1+~3.1.0+~0.16.6+~cs1.4.4-3 |
| Ubuntu 25.10 | jupyterlab | no fix |
| Ubuntu 26.04 LTS | jupyterlab | no fix |
| Ubuntu 26.10 | jupyterlab | no fix |
| openSUSE Tumbleweed | python-jupyterlab | 4.5.7-1.1 |
| openSUSE Tumbleweed | python-notebook | 7.5.6-1.1 |