CVE-2026-42557jupyterlab: Command linker attributes in HTML enable one-click command execution from untrusted content
Description
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.
Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.
Affected products and versions
| Vendor | Product | Versions | |
|---|---|---|---|
| jupyter | jupyterlab | < 4.5.7 | |
| jupyter | notebook | >= 7.0.0, < 7.5.6 | |
| jupyterlab | jupyterlab | < 4.5.7 | |
| migration toolkit applications | 8.2 | — | |
| openshift ai | 3.4 | — | |
| Red Hat | Red Hat Migration Toolkit for Applications 8.2 | all versions | |
| Red Hat | Red Hat OpenShift AI 3.4 | all versions | |
| Red Hat | Red Hat OpenShift AI (RHOAI) | all versions |
References and patches
- https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-mqcg-5x36-vfcg MitigationVendor Advisory
- https://access.redhat.com/errata/RHSA-2026:43038
- https://access.redhat.com/errata/RHSA-2026:60520
- https://access.redhat.com/security/cve/CVE-2026-42557
- https://bugzilla.redhat.com/show_bug.cgi?id=2477086
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42557.json
CPE matches (NVD) (2)
cpe:2.3:a:jupyter:jupyterlab:*:*:*:*:*:*:*:*< 4.5.7cpe:2.3:a:jupyter:notebook:*:*:*:*:*:*:*:*≥ 7.0.0 < 7.5.6