CVE-2026-45707
n8n-MCP: Multi-tenant MCP requests fall back to process-level n8n credentials when tenant headers are absent or incomplete
- State
- Published
- Severity
- 8.1 High
- Published
- May 29, 2026
- Updated
- Jun 1, 2026
- Reserved
- May 13, 2026
Description
n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. Prior to 2.51.2, when ENABLE_MULTI_TENANT=true, the HTTP transport documents that the target n8n instance is selected per-request from x-n8n-url / x-n8n-key headers. Requests that omitted those headers — or supplied only one of them — silently fell back to the process-level N8N_API_URL / N8N_API_KEY credentials configured for the operator's own n8n instance. As a result, an authenticated MCP tenant could cause n8n management calls to execute against the operator's instance instead of its own. This affects HTTP-mode deployments of n8n-mcp that are run as a shared multi-tenant service. Single-tenant deployments (ENABLE_MULTI_TENANT unset or false) are not affected. This vulnerability is fixed in 2.51.2.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 8.1 High | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N | GitHub_M |
Weaknesses
- CWE-284 Improper Access Control
Affected Products
| Product | Versions |
|---|---|
n8n-mcpczlonkowski |
|
References
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