GHSA-f3rg-xqjj-cj9w is a medium-severity (CVSS 6.5) CWE-201 vulnerability in n8n-mcp. O3 Security confirms whether GHSA-f3rg-xqjj-cj9w is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
n8n-MCP: Workflow telemetry sanitizer could retain partial values from URL-shaped node parameters
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-f3rg-xqjj-cj9w.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-f3rg-xqjj-cj9w plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 0 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
n8n-mcpnpmDescription
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | n8n-mcp | all versions | 2.51.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for n8n-mcp. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update n8n-mcp to 2.51.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f3rg-xqjj-cj9w is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-f3rg-xqjj-cj9w is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-f3rg-xqjj-cj9w. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-f3rg-xqjj-cj9w in your dependencies?
O3 detects GHSA-f3rg-xqjj-cj9w across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.