Server-side Request Forgery (SSRF) Affecting n8n-mcp package, versions >=2.17.1 <2.47.14
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-JS-N8NMCP-16415906
- published4 May 2026
- disclosed30 Apr 2026
- creditmanthanghasadiya
Introduced: 30 Apr 2026
NewCVE-2026-42449 (opens in a new tab)How to fix?
Upgrade n8n-mcp to version 2.47.14 or higher.
Overview
n8n-mcp is an Integration between n8n workflow automation and Model Context Protocol (MCP)
Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF) via the SSRFProtection.validateUrlSync function in the src/utils/ssrf-protection.ts component. An attacker can reach internal services and cloud metadata endpoints by supplying IPv6-literal URLs such as IPv4-mapped, IPv4-compatible, 6to4, NAT64, ULA, or site-local addresses that bypass the synchronous URL validation. This lets user-controlled InstanceContext values in the SDK embedder path reach the HTTP client, exposing the x-n8n-api-key and allowing requests to localhost, RFC1918 networks, and metadata services.
Workarounds
- Reject any
n8nApiUrlwhose hostname is an IP literal, including bracketed IPv6 and dotted IPv4, before passing it toN8NDocumentationMCPServerorgetN8nApiClient(). This prevents attacker-supplied URLs from reaching internal services or cloud metadata endpoints. - Do not accept user-controlled
n8nApiUrlvalues; derive the URL only from internal configuration. This removes the SSRF entry point entirely for SDK embedder deployments. - Restrict outbound network access from the
n8n-mcpprocess to RFC1918 ranges (10.0.0.0/8,172.16.0.0/12,192.168.0.0/16), link-local169.254.0.0/16, and cloud metadata endpoints. This limits SSRF blast radius even if a malicious URL is supplied.