Executive brief
n8n is an automation platform used to connect different software services and automate business workflows. A security flaw in its browser-control component allows unauthorized individuals to remotely take control of a user's web browser if the system is configured in a specific way. An attacker could use this to navigate to websites, run malicious scripts, or steal sensitive information like login cookies and saved data from the user's browser profile.
Technical details
A missing authentication vulnerability (CWE-306) exists in the @n8n/mcp-browser component of n8n when configured to use HTTP transport (--transport http). The Model Context Protocol (MCP) endpoint fails to validate requests, allowing any network-reachable attacker to initialize sessions and invoke browser-control tools. If the n8n AI Browser Bridge extension is active, an attacker can perform JavaScript evaluation, navigate the browser, and access cookies or local storage within the user's active browser profile. The default 'stdio' transport is not affected. Patches are available in versions 2.25.7 and 2.26.2.
Affected products
- n8n-io n8n < 2.25.7, >= 2.26.0 < 2.26.2
Timeline
- 2026-06-10: advisory: GitHub advisory published by vendor
- 2026-06-23: disclosed: NVD publication date