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n8n-mcp has unauthenticated session termination and information disclosure in HTTP transport

High severity GitHub Reviewed Published Apr 10, 2026 in czlonkowski/n8n-mcp • Updated Apr 10, 2026

Package

npm n8n-mcp (npm)

Affected versions

<= 2.47.5

Patched versions

2.47.6

Description

Summary

Several HTTP transport endpoints in n8n-mcp lacked proper authentication, and the health check endpoint exposed sensitive operational metadata without credentials.

Impact

An unauthenticated attacker with network access to the n8n-mcp HTTP server could disrupt active MCP sessions and gather information useful for further attacks.

Patches

Fixed in v2.47.6. All MCP session endpoints now require Bearer authentication. The health check endpoint has been reduced to a minimal liveness response.

Workarounds

If you cannot upgrade immediately:

  • Restrict network access to the HTTP server using firewall rules, reverse proxy IP allowlists, or a VPN so that only trusted clients can reach it.
  • Use stdio mode (MCP_MODE=stdio) instead of HTTP mode. The stdio transport does not expose any HTTP endpoints and is unaffected by this vulnerability.

Upgrading to v2.47.6 is still strongly recommended.

Credit

Reported by @yotampe-pluto.

References

@czlonkowski czlonkowski published to czlonkowski/n8n-mcp Apr 10, 2026
Published to the GitHub Advisory Database Apr 10, 2026
Reviewed Apr 10, 2026
Last updated Apr 10, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

EPSS score

Weaknesses

Missing Authentication for Critical Function

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources. Learn more on MITRE.

CVE ID

No known CVE

GHSA ID

GHSA-75hx-xj24-mqrw

Source code

Credits

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