CVE-2026-86073Network attack vector

OAuth consent bypass via unbound refresh-token resource

Published Sep 8, 2026 · Updated Sep 9, 2026

Improper authorization in the n8n OAuth token endpoint before 2.37.7 and in 2.38.0 allows remote attackers to access unapproved workflows. Refresh-token records omit the consented resource, so rotation accepts any registered resource URL supplied by the client instead of enforcing the original grant. Exploitation requires a registered OAuth client, an authenticated user's approval for one protected workflow, and knowledge of another workflow that user can execute.

CVSS severity5.9
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authorization in the n8n OAuth token endpoint before 2.37.7 and in 2.38.0 allows remote attackers to access unapproved workflows. Refresh-token records omit the consented resource, so rotation accepts any registered resource URL supplied by the client instead of enforcing the original grant. Exploitation requires a registered OAuth client, an authenticated user's approval for one protected workflow, and knowledge of another workflow that user can execute.

The record

CVE
CVE-2026-86073
Published
Sep 8, 2026
Updated
Sep 9, 2026
Vendor
n8n
Product
n8n
Classifications
T1550.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 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=< 2.37.7
  2. Affected versionversion=>= 2.38.0, < 2.38.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

n8n · n8nversion=< 2.37.7; version=>= 2.38.0, < 2.38.1

Published CVSS scores

5.9n8nCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:L/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1550.001Application Access Token

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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