{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "n8n-mcp"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.50.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-200",
      "CWE-22",
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-08T17:00:09Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "## Impact\n\n`n8n-mcp` versions before 2.50.1 contained three independently-reported issues affecting deployments that run the n8n API integration:\n\n1. **Caller-supplied identifiers were not validated before being used as URL path segments** by the n8n API client. An authenticated MCP caller passing a crafted workflow id could cause outbound requests carrying the configured n8n API key to land on other same-origin endpoints, bypassing handler-level access controls (including `DISABLED_TOOLS`).\n\n2. **Validated webhook, form, and chat trigger URLs followed redirects.** A URL that passed initial validation could redirect the outbound request to a host that would otherwise have been rejected, with the response body returned to the caller. Reachable as non-blind SSRF over authenticated MCP calls.\n\n3. **Mutation telemetry stored unredacted operation payloads.** On instances running with the default opt-in telemetry, partial-update operation diffs were uploaded without redaction. Operation values can carry the same node-parameter values the workflow contains, including bearer tokens, API keys, and webhook secrets.\n\n## Severity\n\nCVSS 8.3 (HIGH). Exploitation requires an authenticated MCP caller and an n8n API integration configured with an n8n API key.\n\n## Patched versions\n\nUpgrade to `n8n-mcp \u003e= 2.50.1`.\n\n## Workarounds\n\n- For issues (1) and (2): restrict network access to the HTTP transport (firewall, reverse-proxy ACL, or VPN) so only trusted callers can reach the MCP HTTP port; or switch to stdio mode, which exposes no HTTP surface for these issues.\n- For issue (3): set `N8N_MCP_TELEMETRY_DISABLED=true` in the environment before starting the server, or run `npx n8n-mcp telemetry disable` once.\n\n## Credit\n\nReported by @cybercraftsolutionsllc.",
  "id": "GHSA-8g7g-hmwm-6rv2",
  "modified": "2026-05-08T17:00:09Z",
  "published": "2026-05-08T17:00:09Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-8g7g-hmwm-6rv2"
    },
    {
      "type": "WEB",
      "url": "https://github.com/czlonkowski/n8n-mcp/commit/1cfe9c6bddb4b1634e6e23323c18ea35fd196999"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/czlonkowski/n8n-mcp"
    },
    {
      "type": "WEB",
      "url": "https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.50.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "n8n-mcp affected by path traversal, redirect-following SSRF, and telemetry payload exposure"
}