Understanding the n8n-MCP Information Disclosure Vulnerability
A security vulnerability, identified as CVE-2026-42282, has been discovered in n8n-MCP, an MCP server designed to provide AI assistants with access to n8n node documentation and operations. This flaw could lead to the unintended exposure of sensitive information in server logs, posing a risk to the confidentiality of user credentials.
CVE Details
- Product: n8n-MCP
- CVE ID: CVE-2026-42282
- Published Date: May 8, 2026
- Severity: Medium
- Status: Analyzed
Affected Products
This vulnerability affects n8n-MCP versions prior to 2.47.13. Specifically, when n8n-MCP is configured to run in HTTP transport mode, and authenticated requests are made to MCP tools, the full arguments and JSON-RPC parameters of these requests were logged unredacted. This means that if these requests carried sensitive data like credentials, those values could be stored directly in your server logs.
Current Status
The good news is that this information disclosure vulnerability has been officially recognized and addressed. A patch has been released in n8n-MCP version 2.47.13. This update ensures that sensitive data in authenticated requests is properly redacted before being written to server logs, mitigating the risk of accidental disclosure.
Severity Level
The vulnerability has been assigned a Medium severity rating with a CVSS score of 4.3. While it does not allow unauthenticated attackers to directly exploit the system, it could lead to the disclosure of critical information if logs are accessible to unauthorized individuals or external systems. The exposure of data such as bearer tokens, OAuth credentials, API keys, webhook authentication headers, or other secret payloads could have significant security implications, enabling further attacks or unauthorized access to other systems.
Possible Solutions
To protect your n8n-MCP deployments from this information disclosure vulnerability, the most critical step is to update to version 2.47.13 or later. This version includes the necessary patch to redact sensitive arguments and parameters from server logs. System administrators and developers should prioritize this update to secure their environments. Regularly reviewing and securing your log collection and storage practices is also a crucial complementary measure.
References
https://github.com/czlonkowski/n8n-mcp/commit/59b665bda36797823df238aeaf20adb862c9f451
https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.47.13
https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-wg4g-395p-mqv3
