CVE-2026-54309 Details
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.
A vulnerability exists in n8n versions prior to 2.25.7 and 2.26.2, specifically when the @n8n/mcp-browser package is used in HTTP transport mode. In this configuration, the MCP endpoint allows session initialization and tool invocation requests without authentication. This oversight enables any network-accessible client or website to initiate an MCP session and use browser-control tools. If the n8n AI Browser Bridge extension is active, an unauthenticated user can manipulate browser functions such as navigation, JavaScript execution, and access cookies and storage, all through the user's actual browser profile. This issue is not present when @n8n/mcp-browser operates with the default stdio transport, which is unaffected.
Users should upgrade to n8n versions 2.25.7 or 2.26.2 or later. If an immediate upgrade is not possible, n8n administrators can avoid using the HTTP transport with @n8n/mcp-browser, or if HTTP transport is necessary, restrict network access to the listening port to trusted clients only.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 23, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/n8n-io/n8n/security/advisories/GHSA-qrx8-25qr-5r7v | [email protected] | MitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-306 | Missing Authentication for Critical Function | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| n8n n8n | < 2.25.7 >= 2.26.0, < 2.26.2 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 25, 2026 | Initial Analysis | [email protected] |
| Jun 23, 2026 | CVE Modified | CISA-ADP |
| Jun 23, 2026 | New CVE Received | [email protected] |