Jupyter: JupyterLab PluginManager lock-rule enforcement bypass

JupyterLab's plugin manager exposes administrator controls intended to prevent users from enabling or disabling selected plugins. Two server-side enforcement gaps let an authenticated user bypass those controls with direct requests to /lab/api/plugins.

Impact

Users could workaround the plugin manager lock rules via direct API access for either: - child plugins of extensions covering multiple plugins - when "lock all" was issued by the administrator

The integrity of data can be impacted, and any hardening or restrictions on permitted user actions (e.g. download/upload limits) within the single-user server can be circumvented if those were implemented with plugins that were locked using the faulty mechanisms.

Patches

JupyterLab [v4.6.2](https://github.com/jupyterlab/jupyterlab/releases/tag/v4.6.2) and [v4.5.10](https://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.10) contain the patch.

Users of applications that depend on JupyterLab, such as Notebook v7+, should update jupyterlab package too.

Workarounds

Manually lock all plugins that should be locked. The core plugin identifiers can be found in [the documentation](https://jupyterlab.readthedocs.io/en/latest/extension/extension_points.html#core-plugins) and identifiers for all installed extensions are listed in the [Plugin Manager](https://jupyterlab.readthedocs.io/en/latest/user/extensions.html#managing-plugins-with-plugin-manager).