JupyterLab versions >=3.3.0 <4.5.10 and >=4.6.0 <4.6.2 allow cross-site scripting (XSS) via crafted overrides.json settings files. The vulnerability occurs because notebook display settings imported through the Settings Editor's Import button or loaded automatically from shared directories are not properly validated, enabling embedded code execution within JupyterLab. This can lead to arbitrary code execution with the affected user's privileges, including reading/modifying notebooks and running code on connected kernels. Attackers require either write access to shared settings directories (for automatic application without user action) or user interaction to import a malicious settings file. Patches fixing this issue were released in versions 4.5.10 and 4.6.2. Administrators are advised to restrict write permissions on configuration directories and implement trusted configuration distribution.

Exploitation of this vulnerability allows an attacker to execute arbitrary code within the context of the affected user in JupyterLab. This includes reading and modifying the user's notebooks and files and running code on the user's behalf through the notebook server and any connected kernels. If an attacker has write access to shared settings directories, they can plant a malicious overrides.json file that is automatically applied without user interaction. Alternatively, a user can be tricked into importing a malicious settings file, leading to code execution. The impact is high due to the ability to run arbitrary code with user privileges and potentially compromise user data and environment.

Official patches are available in JupyterLab versions 4.5.10 and 4.6.2; users should upgrade to these or later versions to remediate this vulnerability. There are no known workarounds. Administrators should restrict write permissions on application settings directories and other Jupyter configuration paths on multi-tenant or shared file systems to prevent unauthorized placement of malicious overrides.json files. It is recommended to establish a trusted process for distributing configuration files rather than relying on ad-hoc importing of shared settings files.