CVE-2026-45582: n8n-MCP: Workflow telemetry sanitizer could retain partial values from URL-shaped node parameters

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-29 · updated 2026-07-21
Weakness: CWE-201

Description

n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. Prior to 2.51.3, the workflow telemetry sanitizer could retain partial fragments of URL-shaped node parameters before sending workflow data to the project's anonymous telemetry backend. Values placed in HTTP-Request-style node parameters — such as customer or tenant identifiers, short secrets embedded in query strings, and signed request parameters — could therefore appear in stored telemetry, contrary to the collection boundary documented in PRIVACY.md. This vulnerability is fixed in 2.51.3.

Affected products

czlonkowski n8n-mcp: before 2.51.3 — fixed in 2.51.3

How to fix

Upgrade to a fixed version: czlonkowski n8n-mcp 2.51.3. Check the vendor advisory for mitigations.

References

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