A significant security vulnerability has been identified in n8n-MCP, an MCP server designed to provide AI assistants with access to n8n node documentation, properties, and operations. This flaw, tracked as CVE-2026-55608, could allow unauthorized access to sensitive workflow backup data in certain multi-tenant configurations.
CVE Details
Product: n8n-MCP
Published: July 15, 2026
Severity: Medium
Status: Analyzed
Affected Products
The vulnerability impacts versions of n8n-MCP prior to 2.57.4. Specifically, deployments configured for multi-tenant HTTP mode with the ENABLE_MULTI_TENANT=true setting are at risk.
Current Status
This vulnerability has been officially analyzed. A fix has been released, and users are strongly encouraged to update their installations.
Severity Level
Rated as Medium, this vulnerability could allow an authenticated tenant to bypass intended access restrictions. In vulnerable versions, an attacker could access or even delete workflow-version backups that belong to the default system scope, rather than being confined to their own tenant’s data. This improper access control exposes potentially sensitive information from prior single-tenant deployments or migrations.
Possible Solutions
The good news is that a patch is available. Users of affected n8n-MCP installations should upgrade to version 2.57.4 or later immediately.
The fix addresses the issue by enforcing stricter authorization checks in multi-tenant HTTP mode. Previously, a request missing either the x-n8n-url or x-n8n-key header could inadvertently gain access to default-scope backups. Version 2.57.4 ensures that for multi-tenant setups, both of these tenant-specific headers must be present and valid for any request attempting to access workflow version backups. This prevents incomplete or partial tenant contexts from being able to view or manipulate sensitive data outside of their designated scope.
References
https://github.com/czlonkowski/n8n-mcp/commit/1f42899749ed0c584fb6b4fd63d75233c3edee59
https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.57.4
https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-2cf7-hpwf-47h9
