CVE-2026-42230

n8n: Open Redirect in MCP OAuth Consent Flow

Published May 4, 2026 CVSS 4.0 · 5.1 Medium EPSS < 1% KEV · Not listed
Description
n8n is an open source workflow automation platform. Prior to versions 1.123.32, 2.17.4, and 2.18.1, the /mcp-oauth/register endpoint accepted OAuth client registrations without authentication, allowing arbitrary redirect_uri values to be registered. When a user denies the MCP OAuth consent dialog, the handleDeny handler redirects the user to the registered redirect_uri without validation, enabling an open redirect to an attacker-controlled URL. An attacker can craft a phishing link and send it to a victim; if the victim clicks "Deny" on the consent page, they are silently redirected to an external site. This issue has been patched in versions 1.123.32, 2.17.4, and 2.18.1.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-f6x8-65q6-j9m9 n8n has Open Redirect in MCP OAuth Consent Flow
History
Type Values Removed Values Added
CPEs cpe:2.3:a:n8n:n8n:*:*:*:*:enterprise:node.js:*:*
cpe:2.3:a:n8n:n8n:2.18.0:*:*:*:enterprise:node.js:*:*
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

Type Values Removed Values Added
First Time appeared N8n
N8n n8n
Vendors & Products N8n
N8n n8n
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description n8n is an open source workflow automation platform. Prior to versions 1.123.32, 2.17.4, and 2.18.1, the /mcp-oauth/register endpoint accepted OAuth client registrations without authentication, allowing arbitrary redirect_uri values to be registered. When a user denies the MCP OAuth consent dialog, the handleDeny handler redirects the user to the registered redirect_uri without validation, enabling an open redirect to an attacker-controlled URL. An attacker can craft a phishing link and send it to a victim; if the victim clicks "Deny" on the consent page, they are silently redirected to an external site. This issue has been patched in versions 1.123.32, 2.17.4, and 2.18.1.
Title n8n: Open Redirect in MCP OAuth Consent Flow
Weaknesses CWE-601
References
Metrics cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 4, 2026, 7:56 PM
Reserved
Apr 25, 2026, 5:37 AM
Status
Analyzed
Published
May 4, 2026, 7:16 PM
Modified
Nov 11, 2026, 11:10 PM