CVE-2026-45707

n8n-MCP: Multi-tenant MCP requests fall back to process-level n8n credentials when tenant headers are absent or incomplete

HIGH
8.1
CVSS Score
Published: May 29, 2026 at 01:35 PM UTC
Updated: July 21, 2026 at 01:39 PM UTC
2 products affected across 2 vendorsN8N McpMcp N8N Mcp

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Severity
HIGH8.1
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. Prior to 2.51.2, when ENABLE_MULTI_TENANT=true, the HTTP transport documents that the target n8n instance is selected per-request from x-n8n-url / x-n8n-key headers. Requests that omitted those headers — or supplied only one of them — silently fell back to the process-level N8N_API_URL / N8N_API_KEY credentials configured for the operator's own n8n instance. As a result, an authenticated MCP tenant could cause n8n management calls to execute against the operator's instance instead of its own. This affects HTTP-mode deployments of n8n-mcp that are run as a shared multi-tenant service. Single-tenant deployments (ENABLE_MULTI_TENANT unset or false) are not affected. This vulnerability is fixed in 2.51.2.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.51.2
Affected range stops below 2.51.2, so it looks safe — our inference, not a vendor statement
v < 2.51.2
Affected range stops below 2.51.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

x_refsource_CONFIRMMitigationVendor Advisory
Source: cverecord
https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-jxx9-px88-pj69
x_refsource_MISCProductRelease Notes
Source: cverecord
https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.51.2

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.1HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-284

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