CVE-2026-45707Network attack vector

Cross-tenant data access via environment credential fallback

Published May 29, 2026 · Updated May 29, 2026

Improper access control in n8n-MCP before 2.51.2 allows remote authenticated users to read and write operator n8n data via HTTP. The HTTP transport accepts absent or incomplete x-n8n-url and x-n8n-key tenant headers, after which getN8nApiClient builds a client from process-level N8N_API_URL and N8N_API_KEY. Only shared HTTP deployments with ENABLE_MULTI_TENANT=true are exposed; a tenant can act with the operator key to read or alter workflows, executions, data tables, and credential metadata.

CVSS severity8.1
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in n8n-MCP before 2.51.2 allows remote authenticated users to read and write operator n8n data via HTTP. The HTTP transport accepts absent or incomplete x-n8n-url and x-n8n-key tenant headers, after which getN8nApiClient builds a client from process-level N8N_API_URL and N8N_API_KEY. Only shared HTTP deployments with ENABLE_MULTI_TENANT=true are exposed; a tenant can act with the operator key to read or alter workflows, executions, data tables, and credential metadata.

The record

CVE
CVE-2026-45707
Published
May 29, 2026
Updated
May 29, 2026
Vendor
Ai Advisors Romuald Czlonkowski
Product
n8n-MCP
Classifications
CWE-284, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 29, 2026CVE publishedPublication date reported by the CVE source.
  2. May 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.51.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Ai Advisors Romuald Czlonkowski · n8n-MCPversion=< 2.51.2

Published CVSS scores

8.1GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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