{"id":"CVE-2026-44694","aliases":["EUVD-2026-28825","GHSA-cmrh-wvq6-wm9r"],"status":"published","title":"n8n-MCP: Authenticated SSRF in n8n-mcp webhook and API client paths","description":"n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. From version 2.18.7 to before version 2.50.2, there is an authenticated server-side request forgery vulnerability affecting the webhook trigger tools, the n8n API client (N8N_API_URL), and per-request URLs supplied via the x-n8n-url header in multi-tenant HTTP mode. This issue has been patched in version 2.50.2.","severity":{"version":"4.0","score":7.2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00235,"percentile":0.14582,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-367","CWE-918"],"published":"2026-05-08T16:59:17Z","modified":"2026-10-28T02:30:32Z","fixes":[{"ecosystem":"npm","package":"n8n-mcp","fixed_in":["2.50.2"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"n8n-mcp","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.18.7"},{"fixed":"2.50.2"}]}]},{"source":"osv","ecosystem":"npm","package":"n8n-mcp","ranges":[{"type":"SEMVER","events":[{"introduced":"2.18.7"},{"fixed":"2.50.2"}]}]}],"products":[{"vendor":"czlonkowski","product":"n8n-mcp"},{"vendor":"n8n-mcp","product":"n8n-mcp"}],"references":[{"url":"https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-cmrh-wvq6-wm9r","tags":["x_refsource_CONFIRM","Mitigation","Vendor Advisory","advisory","web"]},{"url":"https://github.com/czlonkowski/n8n-mcp/commit/bcaba839409d470abeb4a6ad9b361b553a1098eb","tags":["x_refsource_MISC","Patch","fix","web"]},{"url":"https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.50.2","tags":["x_refsource_MISC","Product","Release Notes","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44694","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-cmrh-wvq6-wm9r"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44694.json","tags":["advisory"]},{"url":"https://github.com/czlonkowski/n8n-mcp","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-44694","title":"n8n-MCP: Authenticated SSRF in n8n-mcp webhook and API client paths","description":"n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. From version 2.18.7 to before version 2.50.2, there is an authenticated server-side request forgery vulnerability affecting the webhook trigger tools, the n8n API client (N8N_API_URL), and per-request URLs supplied via the x-n8n-url header in multi-tenant HTTP mode. This issue has been patched in version 2.50.2.","status":"published","published":"2026-05-08T19:12:05.326Z","modified":"2026-05-12T02:05:56.224Z","cvss":[{"version":"4.0","score":7.2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L","level":"high","assessor":"cna"}],"cwes":["CWE-367","CWE-918"],"updated_at":"2026-11-02T13:43:00.288193Z"}],"euvd":[{"id":"EUVD-2026-28825","description":"n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. From version 2.18.7 to before version 2.50.2, there is an authenticated server-side request forgery vulnerability affecting the webhook trigger tools, the n8n API client (N8N_API_URL), and per-request URLs supplied via the x-n8n-url header in multi-tenant HTTP mode. This issue has been patched in version 2.50.2.","status":"published","published":"2026-05-08T19:12:05Z","modified":"2026-05-12T02:05:56Z","cvss":[{"version":"4.0","score":7.2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L","level":"high"}],"updated_at":"2026-11-02T19:04:38.653286Z"}],"ghsa":[{"id":"GHSA-cmrh-wvq6-wm9r","title":"n8n-mcp webhook and API client paths has an authenticated SSRF","description":"### Summary\n\nAuthenticated Server-Side Request Forgery affecting the webhook trigger tools, the n8n API client (`N8N_API_URL`), and per-request URLs supplied via the `x-n8n-url` header in multi-tenant HTTP mode.\n\n### Impact\n\nA caller with access to the MCP session can drive HTTP requests from the n8n-mcp host to internal services and cloud metadata endpoints that the SSRF gate is meant to block. The response body is returned to the caller, making internal-service enumeration and credential theft immediate without any out-of-band channel.\n\n- **Multi-tenant HTTP deployments** where tenants share an `AUTH_TOKEN`: any tenant with valid credentials can reach the operator's cloud metadata service and exfiltrate temporary IAM / GCP service account / Azure managed-identity credentials.\n- **Single-tenant deployments**: indirect prompt injection through tool arguments reaches the same surface; an attacker who can influence the LLM's tool calls can read internal services from the n8n-mcp host.\n- **Stdio deployments** are reachable via the same prompt-injection path.\n\n### Patched Versions\n\nFixed in `n8n-mcp@2.50.2`.\n\n**Note for operators:** The same SSRF gate that previously covered webhook URLs now also covers the n8n API client base URL. If `N8N_API_URL` points at `http://localhost:5678` (n8n on the same host) or an RFC1918 address (n8n on the same private network), set `WEBHOOK_SECURITY_MODE=moderate` (allows localhost, still blocks RFC1918 and cloud metadata) or `WEBHOOK_SECURITY_MODE=permissive` (allows RFC1918 too — only safe on a trusted private network). Default `strict` is correct for deployments where n8n is reachable at a public hostname.\n\n### Workarounds\n\nFor deployments that cannot upgrade immediately:\n\n1. **Restrict network egress** from the n8n-mcp host with a firewall, reverse proxy, or cloud security group. Explicitly deny cloud metadata IPs (`169.254.169.254`, `169.254.170.2`, `100.100.100.200`, `192.0.0.192`, and the GCP `metadata.google.internal` resolved IP) and any RFC1918 networks the server does not legitimately need to reach.\n2. **Run in stdio mode** instead of HTTP if the multi-tenant surface is not needed (no shared `AUTH_TOKEN` to compromise).\n3. **Disable workflow management tools** via `DISABLED_TOOLS=n8n_trigger_webhook_workflow,n8n_create_workflow,n8n_test_workflow` if the deployment does not need them.\n\n### Credit\n\nReported by [@fg0x0](https://github.com/fg0x0).","status":"published","published":"2026-05-08T16:59:17Z","modified":"2026-05-13T13:35:06Z","cvss":[{"version":"4.0","score":7.2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L","level":"high"}],"cwes":["CWE-367","CWE-918"],"updated_at":"2026-11-02T14:40:07.01746Z"}],"nvd":[{"id":"CVE-2026-44694","description":"n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. From version 2.18.7 to before version 2.50.2, there is an authenticated server-side request forgery vulnerability affecting the webhook trigger tools, the n8n API client (N8N_API_URL), and per-request URLs supplied via the x-n8n-url header in multi-tenant HTTP mode. This issue has been patched in version 2.50.2.","status":"published","published":"2026-05-08T20:16:31.917Z","modified":"2026-10-26T18:10:00.173Z","cvss":[{"version":"4.0","score":7.2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L","level":"critical","assessor":"primary"}],"cwes":["CWE-367","CWE-918"],"updated_at":"2026-11-02T14:12:18.239974Z"}],"osv":[{"id":"CVE-2026-44694","title":"n8n-MCP: Authenticated SSRF in n8n-mcp webhook and API client paths","description":"n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. From version 2.18.7 to before version 2.50.2, there is an authenticated server-side request forgery vulnerability affecting the webhook trigger tools, the n8n API client (N8N_API_URL), and per-request URLs supplied via the x-n8n-url header in multi-tenant HTTP mode. This issue has been patched in version 2.50.2.","status":"published","published":"2026-05-08T19:12:05.326Z","modified":"2026-10-28T02:30:32.331414737Z","cvss":[{"version":"4.0","score":7.2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L","level":"high"}],"cwes":["CWE-367","CWE-918"],"updated_at":"2026-11-02T15:45:05.172514Z"},{"id":"GHSA-cmrh-wvq6-wm9r","title":"n8n-mcp webhook and API client paths has an authenticated SSRF","description":"### Summary\n\nAuthenticated Server-Side Request Forgery affecting the webhook trigger tools, the n8n API client (`N8N_API_URL`), and per-request URLs supplied via the `x-n8n-url` header in multi-tenant HTTP mode.\n\n### Impact\n\nA caller with access to the MCP session can drive HTTP requests from the n8n-mcp host to internal services and cloud metadata endpoints that the SSRF gate is meant to block. The response body is returned to the caller, making internal-service enumeration and credential theft immediate without any out-of-band channel.\n\n- **Multi-tenant HTTP deployments** where tenants share an `AUTH_TOKEN`: any tenant with valid credentials can reach the operator's cloud metadata service and exfiltrate temporary IAM / GCP service account / Azure managed-identity credentials.\n- **Single-tenant deployments**: indirect prompt injection through tool arguments reaches the same surface; an attacker who can influence the LLM's tool calls can read internal services from the n8n-mcp host.\n- **Stdio deployments** are reachable via the same prompt-injection path.\n\n### Patched Versions\n\nFixed in `n8n-mcp@2.50.2`.\n\n**Note for operators:** The same SSRF gate that previously covered webhook URLs now also covers the n8n API client base URL. If `N8N_API_URL` points at `http://localhost:5678` (n8n on the same host) or an RFC1918 address (n8n on the same private network), set `WEBHOOK_SECURITY_MODE=moderate` (allows localhost, still blocks RFC1918 and cloud metadata) or `WEBHOOK_SECURITY_MODE=permissive` (allows RFC1918 too — only safe on a trusted private network). Default `strict` is correct for deployments where n8n is reachable at a public hostname.\n\n### Workarounds\n\nFor deployments that cannot upgrade immediately:\n\n1. **Restrict network egress** from the n8n-mcp host with a firewall, reverse proxy, or cloud security group. Explicitly deny cloud metadata IPs (`169.254.169.254`, `169.254.170.2`, `100.100.100.200`, `192.0.0.192`, and the GCP `metadata.google.internal` resolved IP) and any RFC1918 networks the server does not legitimately need to reach.\n2. **Run in stdio mode** instead of HTTP if the multi-tenant surface is not needed (no shared `AUTH_TOKEN` to compromise).\n3. **Disable workflow management tools** via `DISABLED_TOOLS=n8n_trigger_webhook_workflow,n8n_create_workflow,n8n_test_workflow` if the deployment does not need them.\n\n### Credit\n\nReported by [@fg0x0](https://github.com/fg0x0).","status":"published","published":"2026-05-08T16:59:17Z","modified":"2026-05-13T13:55:36.573227Z","cvss":[{"version":"4.0","score":7.2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:L/VA:L/SC:H/SI:L/SA:L","level":"high"}],"cwes":["CWE-367","CWE-918"],"updated_at":"2026-11-02T15:46:45.28161Z"}]}}