CVE-2026-42235

n8n is an open source workflow automation platform. Prior to versions 1.123.32, 2.17.4, and 2.18.1, an unauthenticated attacker could register a malicious MCP OAuth client with a crafted client_name. If a victim user authorized the OAuth consent dialog and a second user subsequently revoked that access, a toast notification would render the injected script. Clicking the link would execute arbitrary JavaScript in the victim's authenticated n8n browser session, enabling credential and session token theft, workflow manipulation, or privilege escalation. This issue has been patched in versions 1.123.32, 2.17.4, and 2.18.1.

CVSS v3 9.6 CRITICAL

9.6^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 2.8 / Impact : 6.0

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

References

Link	Resource
https://github.com/n8n-io/n8n/security/advisories/GHSA-537j-gqpc-p7fq	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:n8n:n8n:::::enterprise:node.js::
	cpe:2.3:a:n8n:n8n:::::enterprise:node.js::
	cpe:2.3:a:n8n:n8n:2.18.0::::enterprise:node.js::*

History

No history.

Information

Published : 2026-05-04 19:16

Updated : 2026-06-17 10:47

NVD link : CVE-2026-42235

Mitre link : CVE-2026-42235

CVE.ORG link : CVE-2026-42235

JSON object : View

Products Affected

n8n

n8n

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CWE-87

Improper Neutralization of Alternate XSS Syntax

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