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.
n8n is an open source workflow automation platform. Prior to 2.25.7 and 2.26.2, an authenticated user with permission to create or modify workflows could supply a crafted parameters to the TimescaleDB and/or legacy Postgres v1 node's allowing arbitrary SQL to be injected and executed against the connected database within the privileges of the configured database account. This vulnerability is fixed in 2.25.7 and 2.26.2.
n8n before 2.20.0 contains a credential exfiltration vulnerability in the POST /rest/dynamic-node-parameters/options endpoint that allows authenticated users to bypass Allowed HTTP Request Domains restrictions. Attackers with credential access can cause the n8n server to issue HTTP requests with credentials to unauthorized hosts, exfiltrating sensitive authentication data.
n8n is an open source workflow automation platform. Prior to versions 1.123.32, 2.17.4, and 2.18.1, the MCP OAuth client registration endpoint accepted unauthenticated requests and stored client data without adequate resource controls. An unauthenticated remote attacker could exhaust server memory resources by sending large registration payloads, rendering the n8n instance unavailable. The MCP enable/disable toggle gates MCP access but did not restrict client registrations, meaning the endpoint is reachable regardless of whether MCP access is enabled on the instance. This issue has been patched in versions 1.123.32, 2.17.4, and 2.18.1.
n8n is an open source workflow automation platform. Prior to versions 1.123.33 and 2.17.5, the dynamic-node-parameters endpoints did not verify whether the authenticated caller was authorized to use a supplied credential reference. An authenticated user with access to a shared workflow could supply a foreign credential ID in the request body, causing the backend to decrypt and use that credential in a helper execution path where the caller also controls the destination URL. This allowed the caller to force the backend to authenticate against attacker-controlled infrastructure using a credential belonging to another user, effectively exfiltrating a reusable API key. The issue is not limited to any single node type; any node that resolves credentials dynamically through these endpoints may be affected. This issue has been patched in versions 1.123.33, 2.17.5, and 2.18.0.