medium6.1
CVE-2026-42230
n8n is an open source workflow automation platform.
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | n8n | < 1.123.32 | 1.123.32 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| N8n | N8n | before 1.123.32 from 2.17.0 before 2.17.4 Version 2.18.0 |