CVE-2026-73416Network attack vectorHinoki check available

Prohibited extension installation via noncanonical name comparison

Published Aug 13, 2026 · Updated Aug 13, 2026

Policy bypass in JupyterLab 4.5.0 through 4.5.9 and 4.6.0 through 4.6.1 allows remote authenticated users to install blocked extensions. The PyPI extension manager compares requested names with listing entries using weaker normalization than the canonicalization pip applies, so equivalent spellings evade the policy check. Exploitation requires the PyPI manager, a configured allowlist or blocklist, and kernels and terminals that are disabled or remote; it permits prohibited extension code to alter data or interrupt the user server without new read access.

CVSS severity6.1
Medium
EPSS probability0.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Policy bypass in JupyterLab 4.5.0 through 4.5.9 and 4.6.0 through 4.6.1 allows remote authenticated users to install blocked extensions. The PyPI extension manager compares requested names with listing entries using weaker normalization than the canonicalization pip applies, so equivalent spellings evade the policy check. Exploitation requires the PyPI manager, a configured allowlist or blocklist, and kernels and terminals that are disabled or remote; it permits prohibited extension code to alter data or interrupt the user server without new read access.

The record

CVE
CVE-2026-73416
Published
Aug 13, 2026
Updated
Aug 13, 2026
Vendor
Project Jupyter
Product
JupyterLab
Classifications
CWE-178, CWE-180, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 4.5.0, < 4.5.10
  2. Affected versionversion=>= 4.6.0, < 4.6.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Project Jupyter · JupyterLabversion=>= 4.5.0, < 4.5.10; version=>= 4.6.0, < 4.6.2

Published CVSS scores

6.1GitHubCVSS: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 describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-178Improper Handling of Case Sensitivity
CWE-180Incorrect Behavior Order: Validate Before Canonicalize
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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