CVE-2026-54052

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

Published Jul 15, 2026 CVSS 3.1 · 9.9 Critical 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 2.56.1, 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.

Analysis

Technical impact

The vulnerability in n8n-MCP stems from its local workflow version history backups not being isolated between tenants when the service runs in HTTP mode with multi‑tenancy enabled (ENABLE_MULTI_TENANT=true). An authenticated tenant can therefore read, retrieve, and delete workflow version snapshots that belong to other tenants, exposing full node definitions, credential references, and authorization headers. This constitutes a privilege escalation and authorization failure (CWE‑639 and CWE‑862) that compromises confidentiality, integrity, and availability of data across all tenants. The flaw was addressed in version 2.56.1.

Affected Systems

The affected product is n8n‑MCP (czlonkowski:n8n‑mcp). Versions prior to 2.56.1 that are running in HTTP mode with multi‑tenancy enabled via ENABLE_MULTI_TENANT=true are impacted. No other versions or deployment modes are listed as vulnerable.

Risk and Exploitability

The CVSS base score is 9.9 and the EPSS probability is less than 1 %. The vulnerability is not listed in the CISA KEV catalog. An authenticated tenant can exploit the flaw without additional privileges, making the attack vector relatively low in complexity. The scope spans all tenants, giving an attacker the ability to exfiltrate or destroy sensitive data across the entire instance.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

czlonkowski

n8n-mcp

affected

Version	Status	Constraints
`< 2.56.1`	affected	—

Configuration 1 [-]

cpe:2.3:a:n8n-mcp:n8n-mcp:*:*:*:*:*:*:*:*

No data.

Vendor Product Versions

Czlonkowski

N8n-mcp

Version	Status	Scheme	Platform
`[0,2.56.1)`	affected	semver	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Apply the latest update, upgrading n8n‑MCP to version 2.56.1 or newer.
If an upgrade cannot be performed immediately, disable multi‑tenancy in HTTP mode by setting ENABLE_MULTI_TENANT=false until a patched release is available.
Audit existing backups for unauthorized access and purge any backups that belong to other tenants before applying the patch.

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

Tracking

Advisories

Source	ID	Title
Github GHSA	GHSA-j6r7-6fhx-77wx	n8n-MCP: Cross-tenant access to workflow version backups in multi-tenant HTTP deployments

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Changed

Confidentiality Impact High

Integrity Impact High

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.388% probability within 30 days)

Exploitation none

Automatable no

Technical Impact total

References

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

History

Jul 18, 2026 3:30 AM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}`

Jul 16, 2026 2:45 AM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Czlonkowski Czlonkowski n8n-mcp
Vendors & Products		Czlonkowski Czlonkowski n8n-mcp

Jul 15, 2026 9:00 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

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 2.56.1, 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.
Title		n8n-MCP: Cross-tenant access to workflow version backups in multi-tenant HTTP deployments
Weaknesses		CWE-639 CWE-862
References		https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.56.1 https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-j6r7-6fhx-77wx
Metrics		cvssV3_1 `{'score': 9.9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L'}`