SSRF (Server-Side Request Forgery) in n8n-mcp (CVE-2026-42449)
Summary
SSRF in n8n-mcp (CVE-2026-42449). Confidential information can be exposed externally. Exploitable via N8NDocumentationMCPServer. Mitigation: upgrade to 2.47.14 or later.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-42449 has been found in n8n-mcp.
Attackers can target a specific entry point like N8NDocumentationMCPServer over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.5/10.
What to do: upgrade n8n-mcp to 2.47.14 or later.
If unsure, ask your IT team or search "n8n-mcp CVE-2026-42449" on the vendor's site.
CVE-2026-42449 (n8n-mcp) — CWE-918 / CVSS v3 8.5
Attack vector: remote (network-reachable) / no user interaction
Attack surface: N8NDocumentationMCPServer / n8nApiUrl / n8nApiKey / validateWebhookUrl
Patched: 2.47.14 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
SSRF (CWE-918) exists in n8n-mcp. Attackers reach the vulnerable code path via N8NDocumentationMCPServer.
Check the vendor advisory for the affected versions of n8n-mcp. Attack surface: N8NDocumentationMCPServer / n8nApiUrl / n8nApiKey / validateWebhookUrl.
Severity: High (CVSS 8.5/10). Confidential information can be exposed externally.
Update to 2.47.14.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'n8n-mcp' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'n8n-mcp' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
n8n-mcpを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade n8n-mcp to 2.47.14ステージング環境で 2.47.14 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- patch github.com
- web github.com