CVE-2026-42557

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.
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:jupyter:jupyterlab:*:*:*:*:*:*:*:*
cpe:2.3:a:jupyter:notebook:*:*:*:*:*:*:*:*

History

30 Jun 2026, 03:19

Type Values Removed Values Added
References
  • () 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 -

02 Jun 2026, 18:36

Type Values Removed Values Added
CPE cpe:2.3:a:jupyter:notebook:*:*:*:*:*:*:*:*
cpe:2.3:a:jupyter:jupyterlab:*:*:*:*:*:*:*:*
References () https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-mqcg-5x36-vfcg - () https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-mqcg-5x36-vfcg - Mitigation, Vendor Advisory
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 9.6
First Time Jupyter notebook
Jupyter
Jupyter jupyterlab

13 May 2026, 16:32

Type Values Removed Values Added
New CVE

Information

Published : 2026-05-13 16:16

Updated : 2026-07-15 02:21


NVD link : CVE-2026-42557

Mitre link : CVE-2026-42557

CVE.ORG link : CVE-2026-42557


JSON object : View

Products Affected

jupyter

  • jupyterlab
  • notebook
CWE
CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')