n8n-io n8n up to 2.37.6/2.38.0 OAuth Token Endpoint improper authorization

Summaryinfo

A vulnerability was found in n8n-io n8n up to 2.37.6/2.38.0. It has been declared as critical. The affected element is an unknown function of the component OAuth Token Endpoint. Such manipulation leads to improper authorization. This vulnerability is traded as CVE-2026-86073. The attack may be launched remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in n8n-io n8n up to 2.37.6/2.38.0. Affected by this issue is some unknown processing of the component OAuth Token Endpoint. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality, integrity, and availability. CVE summarizes:

n8n is an open source workflow automation platform. Prior to 2.37.7 and 2.38.1, the OAuth token endpoint bound an authorization code's first access token to the consented resource but did not bind its refresh token. Refreshing checked only that the requested resource was registered, not that it matched the original grant. An OAuth client approved for one workflow could substitute a different workflow URL in the resource parameter and obtain a valid token for an unapproved workflow accessible to the consenting user. This issue is fixed in versions 2.37.7 and 2.38.1.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-86073 since 09/04/2026. The exploitation is known to be easy. The attack may be launched remotely. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1548.002.

Upgrading to version 2.37.7 or 2.38.1 eliminates this vulnerability.

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Productinfo

Vendor

• n8n-io

Name

• n8n

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7
• 2.8
• 2.9
• 2.10
• 2.11
• 2.12
• 2.13
• 2.14
• 2.15
• 2.16
• 2.17
• 2.18
• 2.19
• 2.20
• 2.21
• 2.22
• 2.23
• 2.24
• 2.25
• 2.26
• 2.27
• 2.28
• 2.29
• 2.30
• 2.31
• 2.32
• 2.33
• 2.34
• 2.35
• 2.36
• 2.37
• 2.37.0
• 2.37.1
• 2.37.2
• 2.37.3
• 2.37.4
• 2.37.5
• 2.37.6
• 2.38.0

Website

• Product: https://github.com/n8n-io/n8n/

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