PT-2026-58933 · Npm · N8N-Mcp

Published

2026-07-14

·

Updated

2026-07-14

CVSS v3.1

4.2

Medium

VectorAV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N

Summary

In multi-tenant HTTP mode (ENABLE MULTI TENANT=true), an authenticated tenant could, under certain conditions, reach n8n-mcp's local default-scope workflow versions backups instead of being confined to its own tenant scope. This affects n8n-mcp's own local workflow-version storage, not a normal n8n API capability.

Impact

An authenticated MCP HTTP tenant could read or delete workflow-version backups stored in the default (single-tenant) scope — for example backups left from a prior single-tenant deployment or a migration period. Workflow snapshots may contain sensitive workflow configuration depending on their contents. Single-tenant and stdio deployments are not affected.

Affected versions

<= 2.57.3

Patched version

2.57.4

Remediation

Upgrade to n8n-mcp 2.57.4 or later. The fix requires a complete tenant context in multi-tenant mode and fails closed for workflow-version access that cannot be attributed to a specific tenant.

Workarounds

  • Restrict network access to the HTTP endpoint (firewall / reverse proxy / VPN) so only trusted callers can reach it.
  • Run in stdio mode, which has no multi-tenant HTTP surface.
  • If default-scope backups from a prior single-tenant deployment are not needed, removing them eliminates the exposure.

Credit

Reported by @DavidCarliez.

Fix

Incorrect Authorization

Information Disclosure

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Weakness Enumeration

Related Identifiers

GHSA-2CF7-HPWF-47H9

Affected Products

N8N-Mcp