{"id":"CVE-2026-39974","summary":"n8n-MCP has an Authenticated SSRF via instance-URL header in multi-tenant HTTP mode","details":"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.","aliases":["GHSA-4ggg-h7ph-26qr"],"modified":"2026-07-08T08:12:32.922016582Z","published":"2026-04-09T16:45:20.490Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-918"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39974.json"},"references":[{"type":"WEB","url":"https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.47.4"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39974.json"},{"type":"ADVISORY","url":"https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-4ggg-h7ph-26qr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39974"},{"type":"FIX","url":"https://github.com/czlonkowski/n8n-mcp/commit/d9d847f230923d96e0857ccecf3a4dedcc9b0096"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/czlonkowski/n8n-mcp","events":[{"introduced":"0"},{"fixed":"d9d847f230923d96e0857ccecf3a4dedcc9b0096"}],"database_specific":{"cpe":"cpe:2.3:a:n8n-mcp:n8n-mcp:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"2.47.4"}],"source":["AFFECTED_FIELD","CPE_RANGE","REFERENCES"]}}],"versions":["v2.47.3","v2.47.2","v2.47.1","v2.47.0","v2.46.1","v2.46.0","v2.45.1","v2.45.0","v2.44.1","v2.44.0","v2.43.0","v2.42.3","v2.42.2","v2.42.1","v2.42.0","v2.41.4","v2.41.3","v2.41.2","v2.41.1","v2.41.0","v2.40.5","v2.40.4","v2.40.3","v2.40.2","v2.40.1","v2.40.0","v2.38.0","v2.37.4","v2.37.3","v2.37.2","v2.37.1","v2.36.2","v2.36.1","v2.36.0","v2.35.6","v2.35.5","v2.35.4","v2.35.3","v2.35.2","v2.35.1","v2.35.0","v2.34.5","v2.34.4","v2.34.3","v2.34.2","v2.34.1","v2.34.0","v2.33.6","v2.33.5","v2.33.4","v2.33.3","v2.33.2","v2.33.1","v2.33.0","v2.32.1","v2.32.0","v2.31.9","v2.31.8","v2.31.7","v2.31.6","v2.31.5","v2.31.4","v2.31.3","v2.31.2","v2.31.1","v2.31.0","v2.30.2","v2.30.1","v2.30.0","v2.29.5","v2.29.4","v2.29.3","v2.29.2","v2.29.0","v2.28.9","v2.28.8","v2.28.7","v2.28.6","v2.28.4","v2.28.3","v2.28.2","v2.28.1","v2.28.0","v2.27.2","v2.27.1","v2.27.0","v2.26.5","v2.26.4","v2.26.3","v2.26.2","v2.26.1","v2.26.0","v2.24.1","v2.24.0","v2.23.0","v2.22.21","v2.22.20","v2.22.19","v2.22.18","v2.22.17","v2.22.16","v2.22.15","v2.22.14","v2.22.13","v2.22.12","v2.22.11","v2.22.10","v2.22.9","v2.22.8","v2.22.7","v2.22.6","v2.21.1","v2.21.0","v2.20.8","v2.20.7","v2.20.6","v2.20.5","v2.20.4","v2.20.3","v2.20.2","v2.20.1","v2.20.0","v2.19.6","v2.19.5","v2.19.4","v2.19.3","v2.19.2","v2.19.1","v2.19.0","v2.18.10","v2.18.9","v2.18.8","v2.18.7","v2.18.6","v2.18.5","v2.18.4","v2.18.3","v2.18.1","v2.18.0","v2.17.6","v2.17.5","v2.17.3","v2.17.2","v2.17.1","v2.17.0","v2.16.3","v2.16.2","v2.16.1","v2.16.0","v2.15.6","v2.15.5","v2.15.4","v2.15.3","v2.15.2","v2.15.1","v2.15.0","v2.14.7","v2.14.6","v2.14.5","v2.14.4","v2.14.3","v2.14.2","v2.14.1","v2.14.0","v2.13.2","v2.13.1","v2.13.0","v2.12.2","v2.12.1","v2.12.0","v2.11.3","v2.11.2","v2.10.5","v2.10.4","v2.10.2","v2.10.1","v2.9.1","v2.8.1","v2.7.9"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-39974.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N"}]}