---
id: CVE-2026-54309
title: >-
  n8n: MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control
  Sessions
summary: >-
  n8n: MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control
  Sessions
severity: high
cvss: 10
cwe:
  - CWE-306
vendor: n8n
product: n8n
ecosystem: npm
affected:
  - 'n8n >= 2.26.0, < 2.26.2'
  - n8n < 2.25.7
patched:
  - n8n 2.26.2
  - n8n 2.25.7
published: '2026-06-16'
updated: '2026-06-16'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-qrx8-25qr-5r7v'
references:
  - url: 'https://github.com/n8n-io/n8n/security/advisories/GHSA-qrx8-25qr-5r7v'
  - url: 'https://github.com/advisories/GHSA-qrx8-25qr-5r7v'
tags:
  - ghsa
  - npm
epss: 0.00546
epssPercentile: 0.43376
ingestedAt: '2026-06-29T14:31:47.469Z'
---

## Overview

## Impact
When `@n8n/mcp-browser` is run in HTTP transport mode, the MCP endpoint accepts session initialization and tool invocation requests without any authentication. Any network-reachable client, or any website visited by the user, can establish an MCP session and invoke browser-control tools.

Where the n8n AI Browser Bridge extension is installed and a browser connection is active, an unauthenticated caller can access browser-control capabilities including navigation, JavaScript evaluation, and cookie and storage access against the user's real browser profile.

This issue only affects instances where `@n8n/mcp-browser` is run with the HTTP transport (`--transport http`). The default transport is stdio, which is not affected.

## Patches
The issue has been fixed in n8n versions 2.25.7, and 2.26.2. Users should upgrade to one of these versions or later to remediate the vulnerability.

## Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- Avoid running `@n8n/mcp-browser` with the HTTP transport; use the default stdio transport instead.
- If HTTP transport is required, restrict network access to the listening port to trusted clients only using host-based firewall rules.

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

## Affected packages

- `n8n >= 2.26.0, < 2.26.2`
- `n8n < 2.25.7`

## Remediation

Upgrade to a patched release:

- `n8n 2.26.2`
- `n8n 2.25.7`