CVE-2026-73416
MediumCVSS 6.1Exploitation Probability (EPSS)
Low risk40th percentile - higher than 40% of all known CVEs
Summary
JupyterLab from version 4.5.0 to 4.5.10 and 4.6.2 has a vulnerability in the PyPI extension manager. The enforcement of blocked_extensions_uris uses weaker normalization 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, bypassing the blocklist.
Risk Assessment
An authenticated user can install a prohibited extension, compromising environment integrity and affecting availability, without gaining new read access.
Recommendation
Update JupyterLab to version 4.5.10 or 4.6.2. Additionally, enforce strict allowlist/blocklist controls and monitor extension installations.
Original NVD description (English source)
jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From 4.5.0 until 4.5.10 and 4.6.2, in jupyterlab/extensions/manager.py and jupyterlab/extensions/pypi.py, JupyterLab's PyPI extension manager enforces blocked_extensions_uris by comparing requested install names to blocklist entries with custom 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, and JupyterLab accepts the install request even though pip resolves the variant to the same package. Security impact requires an allowlist or blocklist intended to restrict package installation, the PyPI Extension Manager, and kernels and terminals that are disabled or delegated to remote hosts. The bypass lets an authenticated user install a prohibited extension, defeat integrity restrictions, and affect availability without gaining new read access. This issue is fixed in versions 4.5.10 and 4.6.2.