vulnerability / NVI-00018666 / Revision 1
n8n-MCP: Workflow telemetry sanitizer could retain partial values from URL-shaped node parameters
GitHub lists this reviewed advisory for n8n-mcp. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
6.5 medium
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
n8n-mcp
source listed< 2.51.3
## 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_DISABLED` - `TELEMETRY_DISA
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
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04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
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- GHSA-f3rg-xqjj-cj9w ↗
GitHub Advisory Database · vendor advisory
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Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.