TI-2026-33447 Aliases CVE-2026-45707 GHSA-jxx9-px88-pj69

Improper access control in czlonkowski n8n-mcp

LOW 35CWE-284Published 2026-05-29 · Updated 2026-06-01

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Security bypass
Confidentiality · integrity · availability: High · High · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-284.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00235 14th percentileScored 2026-11-07

Fix Fixed n8n-mcp (czlonkowski): 2.51.2n8n-mcp (npm): 2.51.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
czlonkowski	n8n-mcp	before 2.51.2	2.51.2	Patch available	CNA
—	n8n-mcp (npm)	before 2.51.2	2.51.2	Patch available	GHSA-jxx9-px88-pj69

n8n-mcp Vendorczlonkowski Affected before 2.51.2 Fixed in 2.51.2 Patch available CNA
n8n-mcp (npm) Vendor— Affected before 2.51.2 Fixed in 2.51.2 Patch available GHSA-jxx9-px88-pj69

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:n8n-mcp:n8n-mcp::::::::	before 2.51.2	Vulnerable	czlonkowski

cpe:2.3:a:n8n-mcp:n8n-mcp:*:*:*:*:*:*:*:* Versions before 2.51.2 Vulnerable ·czlonkowski

Remediation

Fix · CNA n8n-mcp (czlonkowski) Fixed in 2.51.2
Fix · GHSA-jxx9-px88-pj69 n8n-mcp (npm) Fixed in 2.51.2 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-45707
2026-10-03 Alias added: GHSA-jxx9-px88-pj69

References

Patch 1

https://github.com/czlonkowski/n8n-mcp/commit/853015d0897be7cf2d9d4726de195c938e4395ab

Advisory 2

Other 2

TI-2026-38986 n8n-MCP: Cross-tenant access to workflow version backups in multi-tenant HTTP deployments CVSS 3.1CRITICAL 9.9
TI-2026-28830 n8n-MCP has an Authenticated SSRF via instance-URL header in multi-tenant HTTP mode CVSS 3.1HIGH 8.5
TI-2026-30738 n8n-MCP: IPv4-mapped IPv6 addresses bypass SSRF protection in validateUrlSync(), enabling full SSRF for SDK embedders CVSS 3.1HIGH 8.5
TI-2026-32585 n8n-MCP: Authenticated SSRF in n8n-mcp webhook and API client paths CVSS 4.0HIGH 7.2
TI-2026-30081 n8n-MCP Logs Sensitive Request Data on Unauthorized /mcp Requests CVSS 3.1MEDIUM 5.3
TI-2026-33331 n8n-MCP: Workflow telemetry sanitizer could retain partial values from URL-shaped node parameters CVSS 3.1MEDIUM 6.5

See all 8 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences