Medium Info disclosure

CVE-2026-55608 — n8n-MCP: Incorrect authorization can expose default-scope workflow version backups in multi-tenant HTTP mode

n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. Prior to 2.57.4, multi-tenant HTTP mode with ENABLE_MULTI_TENANT=true could allow an authenticated tenant to access default-scope workflow_versions backups instead of being confined to the tenant scope, exposing or deleting workflow-version backups from prior single-tenant deployments or migrations. This issue is fixed in version 2.57.4.

Published Jul 15, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

—

No EPSS score.

Affects

Czlonkowski

N8n-mcp

CVSS base

5.4

Medium · 3 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — github.com (NIST National Vulnerability Database)
Documented mitigation — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Czlonkowski N8n-mcp, N8n-mcp N8n-mcp).
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes matching the vulnerability class (info disclosure), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Czlonkowski	N8n-mcp	version < 2.57.4	Vulnerable	CVE Program (cve.org) e CISA ADP
N8n-mcp	N8n-mcp	< 2.57.4	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
5.4	CVSS 3.1	Medium	2.8	2.5	nvd@nist.gov via NIST National Vulnerability Database
4.2	CVSS 3.1	Medium	1.6	2.5	security-advisories@github.com via NIST National Vulnerability Database
4.2	CVSS 3.1	Medium	—	—	GitHub_M via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N (score shown at the top: nvd@nist.gov)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 5.4 (NVD (NIST)) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-200 · Exposure of Sensitive Information

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Look for anomalous data read/export volumes and access to sensitive records.

web/proxy/WAF logsnetwork IDS/IPSapplication logsauthentication logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · czlonkowski/n8n-mcp
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
Fix documented
Oct 15, 2026 · NIST National Vulnerability Database
CVSS changed · 5.4
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Jul 15, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

3 on the record

github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-2cf7-hpwf-47h9
Mitigation, Vendor Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database
github.com/czlonkowski/n8n-mcp/commit/1f42899749ed0c584fb6b4fd63d75233c3edee59
Patch, x_refsource_MISC, NIST National Vulnerability Database
github.com/czlonkowski/n8n-mcp/releases/tag/v2.57.4
Release Notes, x_refsource_MISC, NIST National Vulnerability Database

Elsewhere on this site

Czlonkowski
every CVE for this vendor

Info disclosure
same class

CWE-200
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-54052 n8n-MCP: Cross-tenant access to workflow version backups in multi-tenant HTTP deployments Jul 15, 2026
High CVE-2026-45707 n8n-MCP: Multi-tenant MCP requests fall back to process-level n8n credentials when tenant headers are absent or incomplete May 29, 2026
Medium CVE-2026-45582 n8n-MCP: Workflow telemetry sanitizer could retain partial values from URL-shaped node parameters May 29, 2026
Medium CVE-2026-42282 n8n-MCP: Sensitive MCP tool-call arguments logged on authenticated requests in HTTP mode May 8, 2026
Critical CVE-2026-44694 n8n-MCP: Authenticated SSRF in n8n-mcp webhook and API client paths May 8, 2026
Medium CVE-2026-41495 n8n-MCP Logs Sensitive Request Data on Unauthorized /mcp Requests May 8, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No FIRST EPSS score.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-55608 is "n8n-MCP: Incorrect authorization can expose default-scope workflow version backups in multi-tenant HTTP mode", rated Medium. It affects N8n-mcp (Czlonkowski); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.4 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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