CVE-2026-55608

n8n-MCP: Incorrect authorization can expose default-scope workflow version backups in multi-tenant HTTP mode

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Published Jul 15, 2026 CVSS 3.1 · 4.2 Medium EPSS < 1% KEV · Not listed
Description
n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. Prior to 2.57.4, multi-tenant HTTP mode with ENABLE_MULTI_TENANT=true could allow an authenticated tenant to access default-scope workflow_versions backups instead of being confined to the tenant scope, exposing or deleting workflow-version backups from prior single-tenant deployments or migrations. This issue is fixed in version 2.57.4.

Analysis

AI-generated

Technical impact

The flaw in n8n-MCP allows an authenticated tenant to view or delete workflow-version backups that belong to the default scope instead of being limited to the tenant's own scope. This misuse of authorization exposes sensitive backup data and can lead to data loss. The weakness corresponds to information exposure (CWE-200) and improper authorization control (CWE-863).

Affected Systems

n8n-MCP is the affected product, provided by the vendor czlonkowski. Any installation running a version earlier than 2.57.4 in multi-tenant HTTP mode with ENABLE_MULTI_TENANT set to true is vulnerable. The issue is fixed starting with release 2.57.4.

Risk and Exploitability

The CVSS score of 4.2 indicates a low-to-medium severity. The EPSS score of < 1% means that the likelihood of exploitation is very low, and the vulnerability is not listed in CISA KEV. Exploitation requires an authenticated tenant; the attacker can read or delete default-scope workflow-version backups but cannot gain higher-level privileges.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade n8n-MCP to version 2.57.4 or later.
  • If multi-tenant functionality is not required, set ENABLE_MULTI_TENANT to false or remove the configuration.
  • Apply stricter access control to the backup API so that tenants can only access their own workflow-version backups.

Generated by OpenCVE AI on July 31, 2026 at 02:46 UTC.

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-2cf7-hpwf-47h9 n8n-MCP: Incorrect authorization can expose default-scope workflow version backups in multi-tenant HTTP mode
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}
Type Values Removed Values Added
First Time appeared Czlonkowski
Czlonkowski n8n-mcp
Vendors & Products Czlonkowski
Czlonkowski n8n-mcp
Type Values Removed Values Added
Description n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. Prior to 2.57.4, multi-tenant HTTP mode with ENABLE_MULTI_TENANT=true could allow an authenticated tenant to access default-scope workflow_versions backups instead of being confined to the tenant scope, exposing or deleting workflow-version backups from prior single-tenant deployments or migrations. This issue is fixed in version 2.57.4.
Title n8n-MCP: Incorrect authorization can expose default-scope workflow version backups in multi-tenant HTTP mode
Weaknesses CWE-200
CWE-863
References
Metrics cvssV3_1

{'score': 4.2, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N'}
Weaknesses
  • CWE-200

    Exposure of Sensitive Information to an Unauthorized Actor

  • CWE-863

    Incorrect Authorization

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 17, 2026, 12:32 PM
Reserved
Jun 16, 2026, 11:31 PM

View source JSON

Updated
Jul 17, 2026, 12:32 PM

JSON

Status
Analyzed
Published
Jul 15, 2026, 9:16 PM
Modified
Oct 24, 2026, 9:10 PM

View source JSON

No data.

Updated
Jul 31, 2026, 3:00 AM

JSON