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.
History

Fri, 14 Aug 2026 10:00:00 +0000

Type Values Removed Values Added
First Time appeared Jupyter
Jupyter jupyterlab
Vendors & Products Jupyter
Jupyter jupyterlab

Thu, 13 Aug 2026 22:15:00 +0000

Type Values Removed Values Added
Description 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.
Title jupyterlab: PyPI extension blocklist package-name canonicalization bypass
Weaknesses CWE-178
CWE-180
References
Metrics cvssV4_0

{'score': 6.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-13T22:04:26.603Z

Reserved: 2026-08-12T14:32:11.795Z

Link: CVE-2026-73416

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-13T22:17:25.963

Modified: 2026-08-13T22:17:25.963

Link: CVE-2026-73416

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-14T09:45:05Z