czlonkowski n8n-mcp up to 2.51.1 access control

Summaryinfo

A vulnerability was found in czlonkowski n8n-mcp up to 2.51.1. It has been declared as critical. This affects an unknown part. Such manipulation leads to access control. This vulnerability is documented as CVE-2026-45707. The attack can be executed remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in czlonkowski n8n-mcp up to 2.51.1. It has been rated as critical. Affected by this issue is some unknown processing. The manipulation with an unknown input leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-45707 since 05/13/2026. The exploitation is known to be easy. The attack may be launched remotely. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1068 by the MITRE ATT&CK project.

Upgrading to version 2.51.2 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 853015d0897be7cf2d9d4726de195c938e4395ab is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Artificial Intelligence Software

Vendor

• czlonkowski

Name

• n8n-mcp

Version

• 2.51.0
• 2.51.1

License

• open-source

Website

• Product: https://github.com/czlonkowski/n8n-mcp/

CPE 2.3info

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CPE 2.2info

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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