CVE-2026-73627 in JupyterLab
Summary
by MITRE • 08/13/2026
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.
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Analysis
by VulDB Data Team • 08/13/2026
The vulnerability resides within JupyterLab's plugin management system where administrative lock rules are designed to prevent unauthorized modification of installed extensions. This security flaw affects versions between 4.1.0 and 4.6.1, specifically impacting the server-side enforcement mechanisms that should restrict plugin modifications. The core issue manifests through two distinct enforcement gaps that allow authenticated users to bypass established restrictions through direct API interactions with the /lab/api/plugins endpoint.
The technical implementation of this vulnerability stems from insufficient validation controls within the plugin manager's authorization layer. When administrators implement lock rules through the standard interface, these restrictions should be enforced consistently across all modification pathways. However, the bypass occurs because the system fails to properly validate whether a requested plugin modification operation adheres to existing lock configurations when accessed directly via the REST API endpoint. This represents a classic authorization bypass vulnerability where proper access controls are circumvented through alternative attack vectors.
The operational impact of this vulnerability extends beyond simple unauthorized plugin modifications to potentially compromise data integrity and security hardening measures. An authenticated user can manipulate plugins that were specifically locked by administrators to enforce restrictions such as download/upload limits, or to prevent the execution of potentially malicious extensions. This creates a scenario where attackers with valid credentials can effectively disable security controls that were intentionally implemented to protect the JupyterLab environment from unauthorized modifications.
The vulnerability's classification aligns with CWE-693 - Protection Mechanism Failure and maps to ATT&CK technique T1059.001 - Command and Scripting Interpreter for potential exploitation pathways. The bypass mechanism operates through server-side request manipulation where legitimate authenticated users can directly query the plugin management API endpoint without proper authorization checks that should be enforced regardless of how the request is initiated. This weakness enables privilege escalation within the confines of the JupyterLab application itself, allowing users to circumvent administrative controls that were designed to maintain system integrity.
Security mitigations for this vulnerability require immediate deployment of patches in versions 4.6.2 and 4.5.10 as these releases contain the necessary fixes to properly enforce lock rules across all plugin management interfaces. Organizations should also implement monitoring of API endpoint access patterns for unusual plugin modification activities, particularly around locked extensions. Additionally, administrators should review existing plugin configurations to ensure that no unauthorized modifications have occurred during the vulnerable time period, and consider implementing additional access controls or audit logging to detect similar bypass attempts in other applications with comparable plugin management architectures.