CVE-2026-39974

HIGH
MEDIUM Priority: 0.03 BB Relevance: 67/100
Published: 2026-04-09 Modified: 2026-10-26 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction Conf. Impact Scope Change

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
S: Changed
C: High
I: Low
A: None

Description

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.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
n8n-mcp n8n-mcp < 2.47.4

Bug Bounty Relevance

67 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

8.5 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

EPSS — Exploitation Probability

0.32%
Raw Score 0.003160
Percentile 24.5%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00316
2026-10-28
0.00316

Intelligence Sources

nvd ref →