---
id: "CVE-2026-126386"
page: "https://infrastack.ai/live/CVE-2026-126386"
kind: "vulnerability"
aliases: ["CVE-2026-126386"]
title: "n8n: open redirect in MCP OAuth registration enables phishing"
severity: "medium"
cvss: 5.1
epss: null
exploited: false
status: "open"
category: "ai-tooling"
products: []
ecosystems: []
tags: ["ai-tooling", "mcp", "n8n", "self-hosted"]
not_affected_if: ["fixed-version", "managed-hosting"]
published_at: "2026-11-13T10:17:41+00:00"
first_seen_at: "2026-11-13T10:47:18+00:00"
updated_at: "2026-11-13T10:58:39+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-126386", "first_seen_at": "2026-11-13T10:47:18+00:00"}]
exploit_sources: []
---

# n8n: open redirect in MCP OAuth registration enables phishing

Link for people: https://infrastack.ai/live/CVE-2026-126386 (this .md is for agents)

n8n's MCP OAuth dynamic client registration accepts any redirect_uri without checks, so an unauthenticated attacker can build /mcp-oauth/authorize links that send victims to attacker-controlled sites. The result is phishing that starts from a trusted n8n URL.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the n8n version with `n8n --version` or the instance's About page; versions below `1.123.89`, `2.45.5` (2.x line), `2.46.1` (2.46.x line) or `3.0.1` are affected.
- Check whether MCP OAuth endpoints such as `/mcp-oauth/register` are reachable on the instance.

## Fix

- n8n 1.x: `1.123.89`
- n8n 2.x: `2.45.5`
- n8n 2.46.x: `2.46.1`
- n8n 3.x: `3.0.1`

## Timeline

- 2026-11-13T10:47:18+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-126386

## Documents

- [advisory] Maintainer's advisory: github.com https://github.com/n8n-io/n8n/security/advisories/GHSA-rc3w-8jc8-7x3w
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/n8n-before-1.123.89-open-redirect-via-mcp-oauth-dynamic-client-registration

## From the sources

n8n before 1.123.89, 2.x before 2.45.5, 2.46.x before 2.46.1, and 3.x before 3.0.1 contains an open redirect vulnerability in the unauthenticated MCP OAuth dynamic client registration flow, which accepts arbitrary redirect_uri values via the /mcp-oauth/register endpoint. Attackers can send victims crafted /mcp-oauth/authorize URLs that redirect them to attacker-controlled sites before instance checks run, enabling phishing.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_