JupyterLab's PyPI extension manager enforces blocked_extensions_uris by comparing the requested install name to blocklist entries with a custom string normalization that is weaker than PyPI package-name canonicalization. An authenticated user can request a PyPI-equivalent spelling such as JupyterLab.Git for a blocklisted package such as jupyterlab-git; JupyterLab accepts the install request even though pip resolves the variant to the same package. This has security implications only for deployments that combine all …
JupyterLab's image viewer allows for cross-site scripting (XSS) when a specially-crafted image file is opened through the image viewer and then opened in a new tab. This XSS issue can be used to cause remote code execution (RCE) on the JupyterLab server.
JupyterLab 4.5+ allows notebook settings to be shared and applied through an overrides.json file using the Import button in the Settings Editor. Certain notebook display settings were not properly validated before being applied. As a result, a crafted settings file could contain hidden instructions that run as code inside JupyterLab when imported, instead of only changing a display preference. Because importing a settings file appears harmless, a user could import …
The extension allowlist/blocklist check inside PyPIExtensionManager.install() was not enforced due to a missing await. For purposes of JupyterLab this was a secondary defense-in-depth check: install() was intended to enforce the allowlist/blocklist itself for any future uses and users calling this method directly (in addition to the separate check handling requests arriving through the HTTP API). The only runtime symptom was a RuntimeWarning: coroutine 'is_install_allowed' was never awaited. This has security …
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.
A malicious PyPI package can place a javascript: URL in its [project.urls] metadata. JupyterLab's Extension Manager renders this as the extension's home-page link without validating the protocol, so a user who clicks the extension name executes attacker-controlled JavaScript in the JupyterLab origin.
JupyterLab's HTML sanitizer allowlists data-commandlinker-command and data-commandlinker-args on button elements, while CommandLinker listens for all click events on document.body and executes the named command without checking whether the element came from trusted JupyterLab UI. A notebook with a pre-saved HTML cell output containing a deceptive button can trigger arbitrary JupyterLab commands - including arbitrary code execution - on a single user click, without any code being submitted for execution by …
The allow-list of extensions that can be installed from PyPI Extension Manager (allowed_extensions_uris) is not correctly enforced by JupyterLab prior to 4.5.7. The PyPI Extension Manager was not contained to packages listed on the default PyPI index. This has security implications for deployments that: have allow-listed specific extensions with aim to prevent users from installing packages have the kernel and terminals disabled or delegated to remote hosts (thus no access …
A stored Cross-Site Scripting (XSS) vulnerability in Jupyter Notebook allows attackers to steal authentication tokens from users who open malicious notebook files and interact with elements that the attacker can make look indistinguishable from legitimate controls (single click interaction). The vulnerability enables complete account takeover through the Jupyter REST API, allowing the attacker to: Read all files Modify/create files Access running kernels and execute arbitrary code Create terminals for shell …