CVE-2026-73626Network attack vector

Unauthorized extension installation via unawaited policy check

Published Aug 13, 2026 · Updated Aug 13, 2026

Improper access control in JupyterLab 4.6.0 through 4.6.1 and 4.5.9 and earlier allows remote authenticated users to install disallowed extensions. PyPIExtensionManager.install() invokes the asynchronous is_install_allowed check without awaiting it, so direct calls proceed without enforcing the configured allowlist or blocklist. Exposure requires a custom extension or downstream integration to pass untrusted package names directly, with the PyPI manager enabled and kernels and terminals unavailable locally.

CVSS severity0.0
None
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in JupyterLab 4.6.0 through 4.6.1 and 4.5.9 and earlier allows remote authenticated users to install disallowed extensions. PyPIExtensionManager.install() invokes the asynchronous is_install_allowed check without awaiting it, so direct calls proceed without enforcing the configured allowlist or blocklist. Exposure requires a custom extension or downstream integration to pass untrusted package names directly, with the PyPI manager enabled and kernels and terminals unavailable locally.

The record

CVE
CVE-2026-73626
Published
Aug 13, 2026
Updated
Aug 13, 2026
Vendor
Project Jupyter
Product
JupyterLab
Classifications
CWE-284, CWE-636, T1105
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=0 <4.5.10
  2. Affected versionversion=4.6.0 <4.6.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Project Jupyter · JupyterLabversion=0 <4.5.10; version=4.6.0 <4.6.1

Published CVSS scores

0.0GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A: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-284Improper Access Control
CWE-636Not Failing Securely ('Failing Open')
T1105Ingress Tool Transfer

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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