Jupyter Core is a package for the core common functionality of Jupyter projects. When using Jupyter Core prior to version 5.8.0 on Windows, the shared `%PROGRAMDATA%` directory is searched for configuration files (`SYSTEM_CONFIG_PATH` and `SYSTEM_JUPYTER_PATH`), which may allow users to create configuration files affecting other users. Only shared Windows systems with multiple users and unprotected `%PROGRAMDATA%` are affected. Users should upgrade to Jupyter Core version 5.8.0 or later to receive a patch. Some other mitigations are available. As administrator, modify the permissions on the `%PROGRAMDATA%` directory so it is not writable by unauthorized users; or as administrator, create the `%PROGRAMDATA%\jupyter` directory with appropriately restrictive permissions; or as user or administrator, set the `%PROGRAMDATA%` environment variable to a directory with appropriately restrictive permissions (e.g. controlled by administrators _or_ the current user).