Open Redirect in N8n

CVE-2026-42230

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.

Vulnerability class: Open Redirect

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (19.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 19.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-42230: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

  • N8n — versions 2.18.0
  • N8n-Io N8n — versions < 1.123.32, >= 2.17.0, < 2.17.4, >= 2.18.0, < 2.18.1

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-42230?
CVE-2026-42230 is a medium-severity vulnerability in N8n, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2026-05-04.
How severe is CVE-2026-42230?
Medium severity. CVSS v3 base score is 6.1 out of 10.