← CVE Intelligence

CVE-2026-42557

jupyterlab: Command linker attributes in HTML enable one-click command execution from untrusted content PUBLISHED

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
jupyterlab / jupyterlabaffected < 4.5.7
jupyter / notebookaffected >= 7.0.0, < 7.5.6

CWE

CWE-79

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.

redhat-SADP

A flaw was found in jupyterlab. This vulnerability allows a remote attacker to achieve arbitrary code execution by presenting a user with a specially crafted notebook containing a deceptive button in its pre-saved HTML cell output. When the user clicks this button, the CommandLinker component executes arbitrary JupyterLab commands without sufficient validation, leading to the execution of unauthorized code.