{"id":"CVE-2026-42449","revision":null,"records":[{"revision":"447a7d024ede45adb1034c83e0a506e4","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-42449","aliases":[],"title":"n8n-MCP: IPv4-mapped IPv6 addresses bypass SSRF protection in validateUrlSync(), enabling full SSRF for SDK embedders","description":"n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. In versions 2.47.4 through 2.47.13, the SDK embedder path (N8NDocumentationMCPServer constructor, getN8nApiClient(), and validateInstanceContext()), the synchronous URL validator in SSRFProtection.validateUrlSync() had no IPv6 checks. IPv4-mapped IPv6 addresses such as http://[::ffff:169.254.169.254] bypassed the cloud-metadata, localhost, and private-IP range checks. An attacker able to supply an n8nApiUrl value could cause the server to issue HTTP requests to cloud metadata endpoints, RFC1918 private networks, or localhost services. Response bodies are returned to the caller (non-blind SSRF), and the n8nApiKey is forwarded in the x-n8n-api-key header to the attacker-controlled target. Projects with deployments embedding n8n-mcp as an SDK using N8NDocumentationMCPServer or N8NMCPEngine with user-supplied InstanceContext are affected. The first-party HTTP server deployment was not primarily affected — it has a second async validator (validateWebhookUrl) that catches IPv6 addresses. This issue has been fixed in version 2.47.14. If users are unable to upgrade immediately as a workaround they can validate URLs before passing to the SDK, restrict egress at the network layer, and reject user-controlled n8nApiUrl values.","state":0,"publishedAt":"2026-05-07T20:46:29.429+00:00","modifiedAt":"2026-05-08T14:15:33.465+00:00","affected":[{"ecosystem":"Vendor product","name":"n8n-mcp","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"czlonkowski\",\n                    \"product\": \"n8n-mcp\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 2.47.4, < 2.47.14\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N","score":8.5,"severity":"HIGH"}],"references":["https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-56c3-vfp2-5qqj","https://github.com/czlonkowski/n8n-mcp/commit/9639f757853149f0cb16663cc8b6b6468f27a25f"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-42449","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-42449","identifiers":["CVE-2026-42449"]},"retained":false,"historicalAffected":[]},{"revision":"3d0838a14d7e45ce8ca8fb840e89715e","observedAt":"2026-11-01T07:13:54.901+00:00","statement":{"source":"euvd","id":"EUVD-2026-28442","aliases":["CVE-2026-42449","GHSA-56c3-vfp2-5qqj"],"title":"n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. In versions 2.47.4 through 2.47.13, the SDK embedder path (N8NDocumentationMCPServer constructor, getN8nApiClient(), and vali…","description":"n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. In versions 2.47.4 through 2.47.13, the SDK embedder path (N8NDocumentationMCPServer constructor, getN8nApiClient(), and validateInstanceContext()), the synchronous URL validator in SSRFProtection.validateUrlSync() had no IPv6 checks. IPv4-mapped IPv6 addresses such as http://[::ffff:169.254.169.254] bypassed the cloud-metadata, localhost, and private-IP range checks. An attacker able to supply an n8nApiUrl value could cause the server to issue HTTP requests to cloud metadata endpoints, RFC1918 private networks, or localhost services. Response bodies are returned to the caller (non-blind SSRF), and the n8nApiKey is forwarded in the x-n8n-api-key header to the attacker-controlled target. Projects with deployments embedding n8n-mcp as an SDK using N8NDocumentationMCPServer or N8NMCPEngine with user-supplied InstanceContext are affected. The first-party HTTP server deployment was not primarily affected — it has a second async validator (validateWebhookUrl) that catches IPv6 addresses. This issue has been fixed in version 2.47.14. 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In versions 2.47.4 through 2.47.13, the SDK embedder path (N8NDocumentationMCPServer constructor, getN8nApiClient(), and validateInstanceContext()), the synchronous URL validator in SSRFProtection.validateUrlSync() had no IPv6 checks. IPv4-mapped IPv6 addresses such as http://[::ffff:169.254.169.254] bypassed the cloud-metadata, localhost, and private-IP range checks. An attacker able to supply an n8nApiUrl value could cause the server to issue HTTP requests to cloud metadata endpoints, RFC1918 private networks, or localhost services. Response bodies are returned to the caller (non-blind SSRF), and the n8nApiKey is forwarded in the x-n8n-api-key header to the attacker-controlled target. Projects with deployments embedding n8n-mcp as an SDK using N8NDocumentationMCPServer or N8NMCPEngine with user-supplied InstanceContext are affected. The first-party HTTP server deployment was not primarily affected — it has a second async validator (validateWebhookUrl) that catches IPv6 addresses. This issue has been fixed in version 2.47.14. If users are unable to upgrade immediately as a workaround they can validate URLs before passing to the SDK, restrict egress at the network layer, and reject user-controlled n8nApiUrl values.","state":0,"publishedAt":"2026-05-07T21:16:30.133+00:00","modifiedAt":"2026-10-26T20:10:00.16+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · security-advisories@github.com · Secondary","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N","score":8.5,"severity":"HIGH"}],"references":["https://github.com/czlonkowski/n8n-mcp/commit/9639f757853149f0cb16663cc8b6b6468f27a25f","https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-56c3-vfp2-5qqj"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-42449","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Analyzed","weaknesses":["CWE-918"],"productCriteria":["cpe:2.3:a:n8n-mcp:n8n-mcp:*:*:*:*:*:*:*:*"],"sourceDates":{"published":"2026-05-07T21:16:30.133","lastModified":"2026-10-26T20:10:00.160"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-42449","identifiers":["CVE-2026-42449"]},"retained":false,"historicalAffected":[]},{"revision":"45e4c2b915ff44538c08440b2d63e3e9","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-56c3-vfp2-5qqj","aliases":["CVE-2026-42449"],"title":"n8n-mcp's IPv4-mapped IPv6 addresses bypass SSRF protection in validateUrlSync(), enabling full SSRF for SDK embedders","description":"### Impact\n\nIn the SDK embedder path (`N8NDocumentationMCPServer` constructor, `getN8nApiClient()`, and `validateInstanceContext()`), the synchronous URL validator in `SSRFProtection.validateUrlSync()` had no IPv6 checks. IPv4-mapped IPv6 addresses such as `http://[::ffff:169.254.169.254]` bypassed the cloud-metadata, localhost, and private-IP range checks. An attacker able to supply an `n8nApiUrl` value could cause the server to issue HTTP requests to cloud metadata endpoints (AWS IMDS, GCP, Azure, Alibaba, Oracle), RFC1918 private networks, or localhost services. Response bodies are returned to the caller (non-blind SSRF), and the `n8nApiKey` is forwarded in the `x-n8n-api-key` header to the attacker-controlled target.\n\nThe first-party HTTP server deployment was not primarily affected — it has a second async validator (`validateWebhookUrl`) that catches IPv6 addresses.\n\nImpact category: **CWE-918** (Server-Side Request Forgery).\n\n### Affected\n\nDeployments embedding n8n-mcp as an SDK using `N8NDocumentationMCPServer` or `N8NMCPEngine` with user-supplied `InstanceContext` on versions **v2.47.4 through v2.47.13**.\n\n### Patched\n\n**v2.47.14** and later.\n\n- npm: `npx n8n-mcp@latest` (or pin to `>= 2.47.14`)\n- Docker: `docker pull ghcr.io/czlonkowski/n8n-mcp:latest`\n\n### Workarounds\n\nIf developers cannot upgrade immediately:\n\n- **Validate URLs before passing to the SDK** — reject any `n8nApiUrl` whose hostname is an IP literal (bracketed IPv6 or dotted IPv4) before calling `N8NDocumentationMCPServer` / `getN8nApiClient()`. Accept only URLs with DNS-resolvable hostnames.\n- **Restrict egress at the network layer** — block outbound traffic from the n8n-mcp process to RFC1918 ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16), link-local `169.254.0.0/16`, and cloud metadata endpoints. Defense-in-depth against this class of issue and recommended even after upgrading.\n- **Do not accept user-controlled `n8nApiUrl` values** — if the project's integration derives the URL from internal configuration only, this vulnerability is not reachable.\n\nUpgrading to v2.47.14 is still strongly recommended.\n\n### Credit\n\nReported by @manthanghasadiya.","state":0,"publishedAt":"2026-04-30T18:12:54+00:00","modifiedAt":"2026-05-11T13:53:08.967275+00:00","affected":[{"ecosystem":"npm","name":"n8n-mcp","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"2.47.4"},{"kind":"fixed","version":"2.47.14"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"HIGH"}],"references":["https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-56c3-vfp2-5qqj","https://nvd.nist.gov/vuln/detail/CVE-2026-42449","https://github.com/czlonkowski/n8n-mcp/commit/9639f757853149f0cb16663cc8b6b6468f27a25f","https://github.com/czlonkowski/n8n-mcp"],"sourceUrl":"https://github.com/advisories/GHSA-56c3-vfp2-5qqj","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-56c3-vfp2-5qqj","identifiers":["GHSA-56c3-vfp2-5qqj","CVE-2026-42449"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. 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