n8n-MCP: Workflow telemetry sanitizer could retain partial values from URL-shaped node parameters
Summary
In affected versions of n8n-mcp, 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.
Impact
Operators with access to the project's telemetry backend could read partial fragments of workflow URL parameters that should not have been collected. The bug was scoped to URL-shaped fields in workflow definitions; credentials, OAuth tokens, and workflow execution data are not affected — credentials are removed by a separate code path, and long secrets and known-provider tokens are matched by dedicated patterns.
Patches
Fixed in n8n-mcp 2.51.3. Upgrading is the recommended remediation.
Workarounds
For users who cannot upgrade immediately, disable anonymous telemetry by setting any of these environment variables to true:
N8N_MCP_TELEMETRY_DISABLEDTELEMETRY_DISABLEDDISABLE_TELEMETRY
Credit
Reported by @u-ktdi.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | n8n-mcp | < 2.51.3 | 2.51.3 |
References
- https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-f3rg-xqjj-cj9w
- https://nvd.nist.gov/vuln/detail/CVE-2026-45582
- https://github.com/czlonkowski/n8n-mcp/pull/782
- https://github.com/czlonkowski/n8n-mcp/commit/6cf6fef653fcd6d598f2f356aac4754931c7329f
- https://github.com/czlonkowski/n8n-mcp
- https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.51.3
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N- Weakness (CWE)
CWE-201- Platform
- npm
- Package
n8n-mcp- Disclosed
- 18.05.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-f3rg-xqjj-cj9w - CC BY 4.0
Vulnerability history: n8n-mcp
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 11
- First → latest
- 04.2026 07.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- High 6
- Medium 4
Disclosures per year
- 2026: 11
-
n8n-MCP: Workflow telemetry sanitizer could retain partial values from URL-shaped node parameters this entry
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