CVE-2026-45707: CWE-284: Improper Access Control in czlonkowski n8n-mcp
CVE-2026-45707 is an improper access control vulnerability in n8n-mcp versions prior to 2. 51. 2 when run in multi-tenant HTTP mode. Authenticated tenants could cause management API calls to be executed against the operator's own n8n instance by omitting or partially supplying required headers, leading to unauthorized access. Single-tenant deployments are not affected. The issue is fixed in version 2. 51. 2.
AI Analysis
Technical Summary
The vulnerability in n8n-mcp (before version 2.51.2) occurs when ENABLE_MULTI_TENANT is set to true and the HTTP transport relies on x-n8n-url and x-n8n-key headers to select the target n8n instance per request. If these headers are missing or incomplete, the system falls back to process-level credentials, allowing an authenticated tenant to perform management calls on the operator's own n8n instance rather than their own. This improper access control (CWE-284) affects multi-tenant HTTP-mode deployments and can lead to unauthorized access and control over another tenant's n8n instance.
Potential Impact
An authenticated multi-tenant user can execute management API calls on the operator's n8n instance instead of their own, potentially leading to unauthorized disclosure and modification of sensitive data (confidentiality and integrity impact). Availability is not impacted. The CVSS 3.1 score is 8.1 (High), reflecting network attack vector, low complexity, required privileges, no user interaction, and high confidentiality and integrity impact.
Mitigation Recommendations
This vulnerability is fixed in n8n-mcp version 2.51.2. Users running multi-tenant HTTP-mode deployments should upgrade to version 2.51.2 or later. Single-tenant deployments are not affected. Patch status is not explicitly stated in the vendor advisory, but the fix is included in version 2.51.2. No other mitigations are indicated.
CVE-2026-45707: CWE-284: Improper Access Control in czlonkowski n8n-mcp
Description
CVE-2026-45707 is an improper access control vulnerability in n8n-mcp versions prior to 2. 51. 2 when run in multi-tenant HTTP mode. Authenticated tenants could cause management API calls to be executed against the operator's own n8n instance by omitting or partially supplying required headers, leading to unauthorized access. Single-tenant deployments are not affected. The issue is fixed in version 2. 51. 2.
CVSS v3.1
Score 8.1high
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in n8n-mcp (before version 2.51.2) occurs when ENABLE_MULTI_TENANT is set to true and the HTTP transport relies on x-n8n-url and x-n8n-key headers to select the target n8n instance per request. If these headers are missing or incomplete, the system falls back to process-level credentials, allowing an authenticated tenant to perform management calls on the operator's own n8n instance rather than their own. This improper access control (CWE-284) affects multi-tenant HTTP-mode deployments and can lead to unauthorized access and control over another tenant's n8n instance.
Potential Impact
An authenticated multi-tenant user can execute management API calls on the operator's n8n instance instead of their own, potentially leading to unauthorized disclosure and modification of sensitive data (confidentiality and integrity impact). Availability is not impacted. The CVSS 3.1 score is 8.1 (High), reflecting network attack vector, low complexity, required privileges, no user interaction, and high confidentiality and integrity impact.
Mitigation Recommendations
This vulnerability is fixed in n8n-mcp version 2.51.2. Users running multi-tenant HTTP-mode deployments should upgrade to version 2.51.2 or later. Single-tenant deployments are not affected. Patch status is not explicitly stated in the vendor advisory, but the fix is included in version 2.51.2. No other mitigations are indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-13T04:38:01.166Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a19993ae29bf47b50eaf581
Added to database: 5/29/2026, 1:48:42 PM
Last enriched: 5/29/2026, 2:04:02 PM
Last updated: 5/29/2026, 7:27:28 PM
Views: 12
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