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.