REDHAT-BUG-2467453: High severity jupyter Jupyter Notebook vulnerability

Published May 6, 2026
·
Updated

In Jupyter Notebook versions 7.0.0 through 7.5.5, JupyterLab versions 4.5.6 and earlier, and the corresponding @jupyter-notebook/help-extension and @jupyterlab/help-extension packages before 7.5.6 and 4.5.7, a stored cross-site scripting issue in the help command linker can be chained with attacker-controlled notebook content to steal authentication tokens with a single click.

An attacker can craft a malicious notebook file containing elements that appear indistinguishable from legitimate controls and trigger execution when a user interacts with them. Successful exploitation allows theft of the user's authentication token and complete takeover of the Jupyter session through the REST API, including reading files, creating or modifying files, accessing kernels to execute arbitrary code, and creating terminals for shell access. This issue has been fixed in Notebook 7.5.6, JupyterLab 4.5.7, @jupyter-notebook/help-extension 7.5.6, and @jupyterlab/help-extension 4.5.7. As a workaround, disable the affected help extensions or set allowCommandLinker to false in the sanitizer configuration.

Affected Software

4 affected components
jupyter Jupyter Notebook>=7.0.0<=7.5.5
JupyterLab<=4.5.6
npm/@jupyter-notebook/help-extension<7.5.6
npm/@jupyterlab/help-extension<4.5.7

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Jupyter Notebook to a version that resolves this vulnerability.

    Fixed in 7.5.6
  2. Upgrade

    Upgrade JupyterLab to a version that resolves this vulnerability.

    Fixed in 4.5.7
  3. Upgrade

    Upgrade @jupyter-notebook/help-extension to a version that resolves this vulnerability.

    Fixed in 7.5.6
  4. Upgrade

    Upgrade @jupyterlab/help-extension to a version that resolves this vulnerability.

    Fixed in 4.5.7
  5. Configuration

    Set allowCommandLinker to false in the sanitizer configuration (workaround) to disable the help command linker.

    Jupyter sanitizer configuration allowCommandLinker = false
  6. Configuration

    Disable the affected help extensions (workaround) to prevent execution via the help command linker.

    Jupyter help extensions enabled = false

Event History

May 6, 2026
Data Sourced
via Red Hat·08:01 PM
DescriptionSeverityAffected Software
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