CVE-2025-59842 in Jupyterlab
Summary
by MITRE • 09/26/2025
jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. Prior to version 4.4.8, links generated with LaTeX typesetters in Markdown files and Markdown cells in JupyterLab and Jupyter Notebook did not include the noopener attribute. This is deemed to have no impact on the default installations. Theoretically users of third-party LaTeX-rendering extensions could find themselves vulnerable to reverse tabnabbing attacks if links generated by those extensions included target=_blank (no such extensions are known at time of writing) and they were to click on a link generated in LaTeX (typically visibly different from other links). This issue has been patched in version 4.4.8.
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Analysis
by VulDB Data Team • 10/23/2025
The vulnerability CVE-2025-59842 affects jupyterlab, an extensible environment for interactive and reproducible computing based on the Jupyter Notebook Architecture. This security flaw specifically addresses the improper handling of links generated through LaTeX typesetters in Markdown files and cells within both JupyterLab and Jupyter Notebook applications. The issue manifests when links are created using third-party LaTeX-rendering extensions that include target=_blank attributes, creating a potential security risk that aligns with CWE-1021, which categorizes improper handling of HTML attributes as a weakness in web applications. The vulnerability is classified under the broader category of web security flaws that can lead to reverse tabnabbing attacks, where malicious websites can gain access to the parent window's context through the window.opener property.
The technical flaw stems from the absence of the noopener attribute in links generated by LaTeX typesetters when target=_blank is specified. This attribute is crucial for preventing reverse tabnabbing attacks as it ensures that the newly opened tab cannot access the original window's window.opener property. Without this protection, if a user clicks on a malicious link generated by a third-party LaTeX extension, the attacker's website could potentially access sensitive information from the original JupyterLab or Notebook session. This vulnerability specifically impacts users who utilize third-party extensions for LaTeX rendering, as the default installations of JupyterLab do not exhibit this behavior according to the security advisory. The issue represents a sophisticated attack vector that leverages the legitimate functionality of Markdown rendering to create security risks through improper link handling.
The operational impact of this vulnerability is significant for users who rely on third-party LaTeX rendering extensions within their Jupyter environments. While default installations remain unaffected, users of extended functionality face potential exposure to reverse tabnabbing attacks that could compromise their security context. The attack scenario requires specific conditions including the use of third-party extensions that generate links with target=_blank attributes and user interaction with those links. This vulnerability demonstrates the importance of proper security practices in web application development, particularly in environments where users can install extensions that modify document rendering behavior. The risk is elevated when users navigate to untrusted websites through links generated by LaTeX extensions, as these links are typically visually distinct from regular document links, potentially leading to user confusion and increased susceptibility to social engineering attacks. The vulnerability aligns with ATT&CK technique T1059.001, which involves executing malicious code through user interaction with compromised web content.
The fix implemented in version 4.4.8 addresses this vulnerability by ensuring that all links generated by LaTeX typesetters include the noopener attribute when target=_blank is specified. This patch represents a standard security mitigation approach that follows the principle of least privilege and proper link handling in web applications. Users should upgrade to version 4.4.8 or later to eliminate this security risk. The remediation process involves updating the application software and verifying that no third-party extensions bypass the security measures. Organizations using JupyterLab environments should conduct security assessments to ensure that all installed extensions properly handle link attributes and do not introduce similar vulnerabilities. The vulnerability also underscores the importance of security reviews for extension developers and the need for comprehensive security testing in web-based development environments. This issue serves as a reminder that even seemingly benign functionality can introduce security risks when not properly implemented with security best practices in mind.