CVE-2026-54052

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

State: Published
Severity: 9.9 Critical
Published: Jul 15, 2026
Updated: Jul 18, 2026
Reserved: Jun 11, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	9.9 Critical	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L	GitHub_M

Weaknesses

CWE-639 Authorization Bypass Through User-Controlled Key
CWE-862 Missing Authorization

Affected Products

Product	Versions
n8n-mcpczlonkowski	< 2.56.1Affected

References

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