jupyterlab: PyPI extension blocklist package-name canonicalization bypass

Summary

CVE	CVE-2026-73416
State	PUBLISHED
Assigner	GitHub_M
Source Priority	CVE Program / NVD first with legacy fallback
Published	2026-08-13 22:17:25 UTC
Updated	2026-08-13 22:17:25 UTC
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.

Risk And Classification

Primary CVSS: v4.0 6.1 MEDIUM from [email protected]

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Problem Types: CWE-178 | CWE-180 | CWE-178 CWE-178: Improper Handling of Case Sensitivity | CWE-180 CWE-180: Incorrect Behavior Order: Validate Before Canonicalize

Version	Source	Type	Score	Severity	Vector
4.0	[email protected]	Secondary	6.1	MEDIUM	`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/E:X/C...`
4.0	CNA	DECLARED	6.1	MEDIUM	`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`

CVSS v4.0 Breakdown

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

Present

Privileges Required

Low

User Interaction

None

Confidentiality

Low

Integrity

High

Availability

Low

Sub Conf.

None

Sub Integrity

None

Sub Availability

None

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

Source	Vendor	Product	Version	Platforms
CNA	Jupyterlab	Jupyterlab	affected >= 4.5.0, < 4.5.10	Not specified
CNA	Jupyterlab	Jupyterlab	affected >= 4.6.0, < 4.6.2	Not specified

References

Reference	Source	Link	Tags
github.com/jupyterlab/jupyterlab/security/advisories/GHSA-89vp-jrxv-24w8	[email protected]	github.com
github.com/jupyterlab/jupyterlab/commit/be9303f5bcd5308eaeae953c5a3c9030...	[email protected]	github.com
github.com/jupyterlab/jupyterlab/commit/f1beab4a2027af4719d6edc07d52d6cf...	[email protected]	github.com
github.com/jupyterlab/jupyterlab/pull/19186	[email protected]	github.com
github.com/jupyterlab/jupyterlab/releases/tag/v4.7.0a1	[email protected]	github.com
github.com/jupyterlab/jupyterlab/commit/9365f020baec5221deaf11535ed554c0...	[email protected]	github.com
github.com/jupyterlab/jupyterlab/pull/19184	[email protected]	github.com
github.com/jupyterlab/jupyterlab/pull/19185	[email protected]	github.com
github.com/jupyterlab/jupyterlab/releases/tag/v4.6.2	[email protected]	github.com
github.com/jupyterlab/jupyterlab/releases/tag/v4.5.10	[email protected]	github.com
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

No vendor comments have been submitted for this CVE.

There are currently no legacy QID mappings associated with this CVE.