PYSEC-2026-1478

### Impact Installations of jupyter-lsp running in environments without configured file system access control (on the operating system level), and with jupyter-server instances exposed to non-trusted network are vulnerable to unauthorised access and modification of file system beyond the jupyter root directory.

### Patches Version 2.2.2 has been patched.

### Workarounds Users of jupyterlab who do not use jupyterlab-lsp can uninstall jupyter-lsp.

### Credits We would like to credit Bary Levy, researcher of pillar.security research team, for the discovery and responsible disclosure of this vulnerability.

Edit: based on advice from pillar.security the Confidentiality/Integrity/Availability were increased to High to reflect potential for critical impact on publicly hosted jupyter-server instances lacking isolation of user privileges on operating system level (for best practices please consult https://jupyterhub.readthedocs.io/en/stable/explanation/websecurity.html#protect-users-from-each-other) and CWE-94 was added due to a potential vulnerability chaining in specific environments.