What’s Vulnerable › Vulnerabilities
CVE-2026-54309: n8n: n8n MCP Browser HTTP Transport Exposes Unauthenticated Browser-Control Sessions
- Severity: critical (CVSS 10.0 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-06-23 · updated 2026-10-26
- Weakness: CWE-306
Description
n8n is an open source workflow automation platform. Prior to 2.25.7 and 2.26.2, 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). This vulnerability is fixed in 2.25.7 and 2.26.2.
Affected products
- n8n-io n8n: before 2.25.7; from 2.26.0 before 2.26.2 — fixed in 2.25.7, 2.26.2
How to fix
Upgrade to a fixed version: n8n-io n8n 2.25.7, 2.26.2. Check the vendor advisory for mitigations.
References
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