CVE-2026-54052 | n8n-MCP is an MCP server that provides AI assistants access … | CVSS 9.9 CRITICAL

Description

n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. Prior to 2.56.1, in HTTP mode with multi-tenancy enabled through ENABLE_MULTI_TENANT=true, n8n-mcp's local workflow version history backups were not isolated per tenant, allowing an authenticated tenant to read workflow version snapshots belonging to other tenants and delete or destroy other tenants' stored backups, including full node definitions, credential references, and authorization headers. This issue is fixed in version 2.56.1.

Metadata

CVE ID: CVE-2026-54052
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-06-11 18:24 UTC
Published: 2026-07-15 20:34 UTC
Last updated: 2026-07-15 20:34 UTC
Primary CWE: CWE-639
CWE-639: Authorization Bypass Through User-Controlled Key
Vendor / Product: czlonkowski / n8n-mcp
Sources: cve.org · NVD

Severity & Metrics

9.9 CRITICAL CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L

Affected products (1)

Vendor	Product	Platform	Versions
czlonkowski	n8n-mcp	—	< 2.56.1

Weakness (CWE)

CWE	Source	Description
CWE-639	cna	CWE-639: Authorization Bypass Through User-Controlled Key
CWE-862	cna	CWE-862: Missing Authorization

CVSS scores (1)

Score	Severity	Version	Source	Vector
9.9	CRITICAL	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L

References (2)

https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-j6r7-6fhx-77wx https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-j6r7-6fhx-77wx
https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.56.1 https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.56.1