| Package | Affected versions | Patched versions |
|---|---|---|
| n8n | ≥ 2.26.0, < 2.26.2< 2.25.7 | 2.26.22.25.7 |
| n8n | ≥ 2.26.0, < 2.26.2< 2.25.7 | 2.26.22.25.7 |
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.
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.
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
@n8n/mcp-browser with the HTTP transport; use the default stdio transport instead.These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
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