CVE-2026-55608Network attack vector

Cross-tenant backup access and deletion via incomplete headers

Published Jul 15, 2026 · Updated Jul 15, 2026

Incorrect authorization in n8n-mcp before 2.57.4 allows remote authenticated users to read or delete default-scope workflow backups. The HTTP request gate rejected a multi-tenant request only when both x-n8n-url and x-n8n-key were absent, so either incomplete header pair could reach workflow_versions storage without a complete tenant scope. Exposure requires ENABLE_MULTI_TENANT=true, an authenticated MCP HTTP tenant, and default-scope backups; single-tenant and stdio deployments are unaffected.

CVSS severity4.2
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in n8n-mcp before 2.57.4 allows remote authenticated users to read or delete default-scope workflow backups. The HTTP request gate rejected a multi-tenant request only when both x-n8n-url and x-n8n-key were absent, so either incomplete header pair could reach workflow_versions storage without a complete tenant scope. Exposure requires ENABLE_MULTI_TENANT=true, an authenticated MCP HTTP tenant, and default-scope backups; single-tenant and stdio deployments are unaffected.

The record

CVE
CVE-2026-55608
Published
Jul 15, 2026
Updated
Jul 15, 2026
Vendor
Ai Advisors Romuald Czlonkowski
Product
n8n-MCP
Classifications
CWE-863, CWE-200, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 15, 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=< 2.57.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Ai Advisors Romuald Czlonkowski · n8n-MCPversion=< 2.57.4

Published CVSS scores

4.2GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-863Incorrect Authorization
CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1005Data from Local System

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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