Vulnerability 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.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| N8N | N8N | < 2.25.7 |
Related Weaknesses (CWE)
References
- https://github.com/n8n-io/n8n/security/advisories/GHSA-qrx8-25qr-5r7vMitigationVendor Advisory
FAQ
What is CVE-2026-54309?
CVE-2026-54309 is a vulnerability with a CVSS score of 10.0 (CRITICAL). 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...
How severe is CVE-2026-54309?
CVE-2026-54309 has been rated CRITICAL with a CVSS base score of 10.0/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-54309?
Check the references section above for vendor advisories and patch information. Affected products include: N8N N8N.