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CVE-2026-39974

CVE-2026-39974 · n8n-MCP has an Authenticated SSRF via instance-URL header in multi-tenant HTTP mode

This page contains facts from public vulnerability sources. Check the original advisory before updating.

n8n-MCP is a Model Context Protocol (MCP) server that provides AI assistants with comprehensive access to n8n node documentation, properties, and operations. Prior to 2.47.4, an authenticated Server-Side Request Forgery in n8n-mcp allows a caller holding a valid AUTH_TOKEN to cause the server to issue HTTP requests to arbitrary URLs supplied through multi-tenant HTTP headers. Response bodies are reflected back through JSON-RPC, so an attacker can read the contents of any URL the server can reach — including cloud instance metadata endpoints (AWS IMDS, GCP, Azure, Alibaba, Oracle), internal network services, and any other host the server process has network access to. The primary at-risk deployments are multi-tenant HTTP installations where more than one operator can present a valid AUTH_TOKEN, or where a token is shared with less-trusted clients. Single-tenant stdio deployments and HTTP deployments without multi-tenant headers are not affected. This vulnerability is fixed in 2.47.4.

CVSS 8.5 · High · EPSS 0.3% · Fix available

Published
Updated

Stack: node

Affected products and versions

  • n8n-mcp

    Versions
    • < 2.47.4: Affected

    No fix published

  • n8n-mcp npm

    Affected ranges
    • SEMVER: < 2.47.4

    Update to 2.47.4

Original sources

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