CVE-2026-73627

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).

JupyterLab (pip package 'jupyterlab') versions >=4.1.0,<=4.5.9 and >=4.6.0,<=4.6.1 contain a plugin manager lock-rule enforcement bypass. Two server-side enforcement gaps allow an authenticated user to circumvent administrator lock rules by making direct requests to the /lab/api/plugins endpoint, enabling or disabling plugins that were locked — including child plugins of multi-plugin extensions and plugins locked via the 'lock all' mechanism. This can impact data integrity and bypass hardening or restrictions (e.g., download/upload limits) implemented through locked plugins. Fixed in versions 4.6.2 and 4.5.10.