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Vulnerability · Published May 29, 2026 · Assigned by GitHub_M

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

Medium 6.5

In plain English

A medium-severity security flaw in n8n-mcp from czlonkowski. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 18% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.3%top 82.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

EcosystemPackageFixed inAdvisory
npmn8n-mcp2.51.3GHSA-f3rg-xqjj-cj9w

Affected products (as reported)

VendorProductVersions
czlonkowski n8n-mcp < 2.51.3

Weakness: CWE-201 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

References