CVE-2026-42230

Workarounds

If upgrading is not immediately possible, administrators should consider the following temporary mitigations:

• Restrict network access to the n8n instance to prevent untrusted users from reaching the MCP OAuth endpoints.
• Limit access to the n8n instance to fully trusted users only.

These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

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.

Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites. Typical impact: phishing and credential harvesting via a trusted domain.

CVE-2026-42230 has a CVSS score of 4.7 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.123.32, 2.18.1, 2.17.4); upgrading removes the vulnerable code path.

Kodem intelligence

The issue has been fixed in n8n versions 1.123.32, 2.17.4, and 2.18.1. Users should upgrade to one of these versions or later to remediate the vulnerability.

1. What is CVE-2026-42230? CVE-2026-42230 is a medium-severity open redirect vulnerability in n8n (npm), affecting versions < 1.123.32. It is fixed in 1.123.32, 2.18.1, 2.17.4. Untrusted input controls a URL used for redirection, which can forward users to attacker-controlled sites.
2. How severe is CVE-2026-42230? CVE-2026-42230 has a CVSS score of 4.7 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of n8n are affected by CVE-2026-42230? n8n (npm) versions < 1.123.32 is affected.
4. Is there a fix for CVE-2026-42230? Yes. CVE-2026-42230 is fixed in 1.123.32, 2.18.1, 2.17.4. Upgrade to this version or later.
5. Is CVE-2026-42230 exploitable, and should I be worried? Whether CVE-2026-42230 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-42230 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-42230?
   • Upgrade n8n to 1.123.32 or later
   • Upgrade n8n to 2.18.1 or later
   • Upgrade n8n to 2.17.4 or later