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Vulnerability · Published Jul 15, 2026 · Assigned by GitHub_M

CVE-2026-54052n8n-MCP: Cross-tenant access to workflow version backups in multi-tenant HTTP deployments

Critical 9.9

In plain English

A critical-severity authorization bypass via user-controlled key in n8n-mcp from czlonkowski. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.9Critical
Exploit odds (30 days)0.4%top 66.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
npmn8n-mcp2.56.1GHSA-j6r7-6fhx-77wx

Affected products (as reported)

VendorProductVersions
czlonkowski n8n-mcp < 2.56.1

Weakness: CWE-639, CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L

References