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TI-2026-28830 Aliases CVE-2026-39974GHSA-4ggg-h7ph-26qr

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

Priority LOW 37CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00322 25th percentileScored 2026-11-07
Fix Fixed n8n-mcp (czlonkowski): 2.47.4n8n-mcp (npm): 2.47.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
czlonkowskin8n-mcpbefore 2.47.42.47.4Patch availableCNA
—n8n-mcp (npm)before 2.47.42.47.4Patch availableGHSA-4ggg-h7ph-26qr
  • n8n-mcp Vendorczlonkowski Affected before 2.47.4 Fixed in 2.47.4 Patch available CNA
  • n8n-mcp (npm) Vendor— Affected before 2.47.4 Fixed in 2.47.4 Patch available GHSA-4ggg-h7ph-26qr

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:n8n-mcp:n8n-mcp:*:*:*:*:*:*:*:*before 2.47.4Vulnerableczlonkowski
  • cpe:2.3:a:n8n-mcp:n8n-mcp:*:*:*:*:*:*:*:* Versions before 2.47.4 Vulnerable ·czlonkowski

Remediation

  • Fix · CNA n8n-mcp (czlonkowski) Fixed in 2.47.4
  • Fix · GHSA-4ggg-h7ph-26qr n8n-mcp (npm) Fixed in 2.47.4 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-39974
  2. 2026-10-03 Alias added: GHSA-4ggg-h7ph-26qr

References

Patch 1

Advisory 2

Other 2

  • TI-2026-38986 n8n-MCP: Cross-tenant access to workflow version backups in multi-tenant HTTP deployments CVSS 3.1CRITICAL 9.9
  • TI-2026-30738 n8n-MCP: IPv4-mapped IPv6 addresses bypass SSRF protection in validateUrlSync(), enabling full SSRF for SDK embedders CVSS 3.1HIGH 8.5
  • TI-2026-33447 Improper access control in czlonkowski n8n-mcp CVSS 3.1HIGH 8.1
  • TI-2026-32585 n8n-MCP: Authenticated SSRF in n8n-mcp webhook and API client paths CVSS 4.0HIGH 7.2
  • TI-2026-30081 n8n-MCP Logs Sensitive Request Data on Unauthorized /mcp Requests CVSS 3.1MEDIUM 5.3
  • TI-2026-33331 n8n-MCP: Workflow telemetry sanitizer could retain partial values from URL-shaped node parameters CVSS 3.1MEDIUM 6.5
See all 8 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences