CVE-2026-45707 Details
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.
A vulnerability in n8n-MCP versions prior to 2.51.2 allows authenticated MCP tenants to unintentionally access the operator's n8n instance instead of their own. This issue arises when 'ENABLE_MULTI_TENANT' is set to true and requests to the n8n API lack the necessary 'x-n8n-url' and 'x-n8n-key' headers'. In such cases, the request defaults to using the operator's process-level n8n API credentials, potentially leading to unauthorized management actions on the operator's n8n instance. The vulnerability is present in HTTP-mode deployments of n8n-MCP that are shared multi-tenant services, while single-tenant deployments are not affected.
Upgrade to n8n-MCP version 2.51.2 or later. If an immediate upgrade is not possible, consider disabling multi-tenant mode or rejecting requests without the required tenant headers at a proxy.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 1, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/czlonkowski/n8n-mcp/commit/853015d0897be7cf2d9d4726de195c938e4395ab | [email protected] | Patch |
| https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.51.2 | [email protected] | ProductRelease Notes |
| https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-jxx9-px88-pj69 | [email protected] | MitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-284 | Improper Access Control | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| n8n-mcp n8n-mcp | < 2.51.2 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 21, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 1, 2026 | Initial Analysis | [email protected] |
| May 29, 2026 | New CVE Received | [email protected] |