CVE-2026-44694: CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition in czlonkowski n8n-mcp
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.
AI Analysis
Technical Summary
The vulnerability CVE-2026-44694 in n8n-mcp (versions >= 2.18.7 and < 2.50.2) is a TOCTOU race condition resulting in an authenticated SSRF. It impacts webhook trigger tools, the n8n API client (N8N_API_URL), and URLs provided via the x-n8n-url header when operating in multi-tenant HTTP mode. The race condition allows an attacker with some level of authentication to potentially manipulate server-side requests. The vendor has released a patch in version 2.50.2 to address this issue.
Potential Impact
An attacker with authenticated access can exploit this TOCTOU race condition to perform SSRF attacks, potentially causing unauthorized server-side requests. This could lead to information disclosure or interaction with internal services not intended to be accessible. The CVSS 4.0 base score is 7.2, indicating a high severity impact with network attack vector, requiring low privileges and partial impact on confidentiality, integrity, and availability.
Mitigation Recommendations
A fix for this vulnerability is available in n8n-mcp version 2.50.2. Users should upgrade to version 2.50.2 or later to remediate this issue. Since this is not a cloud service, remediation depends on applying the vendor's patch. Patch status is confirmed by the vendor's versioning information. No additional mitigation guidance is provided in the vendor advisory.
CVE-2026-44694: CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition in czlonkowski n8n-mcp
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-44694 in n8n-mcp (versions >= 2.18.7 and < 2.50.2) is a TOCTOU race condition resulting in an authenticated SSRF. It impacts webhook trigger tools, the n8n API client (N8N_API_URL), and URLs provided via the x-n8n-url header when operating in multi-tenant HTTP mode. The race condition allows an attacker with some level of authentication to potentially manipulate server-side requests. The vendor has released a patch in version 2.50.2 to address this issue.
Potential Impact
An attacker with authenticated access can exploit this TOCTOU race condition to perform SSRF attacks, potentially causing unauthorized server-side requests. This could lead to information disclosure or interaction with internal services not intended to be accessible. The CVSS 4.0 base score is 7.2, indicating a high severity impact with network attack vector, requiring low privileges and partial impact on confidentiality, integrity, and availability.
Mitigation Recommendations
A fix for this vulnerability is available in n8n-mcp version 2.50.2. Users should upgrade to version 2.50.2 or later to remediate this issue. Since this is not a cloud service, remediation depends on applying the vendor's patch. Patch status is confirmed by the vendor's versioning information. No additional mitigation guidance is provided in the vendor advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-07T17:07:09.316Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69fe3b37cbff5d86101fc054
Added to database: 5/8/2026, 7:36:23 PM
Last enriched: 5/8/2026, 7:51:22 PM
Last updated: 5/9/2026, 1:59:22 AM
Views: 23
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