CVE-2026-41495 — n8n-mcp
MEDIUMCVE-2026-41495 is a medium-severity (CVSS 5.3) CWE-532 vulnerability in n8n-mcp. A fix is available for n8n-mcp — see the affected versions and patch details below.
n8n-MCP Logs Sensitive Request Data on Unauthorized /mcp Requests
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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 CVE-2026-41495.
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
CVE-2026-41495 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 378,156 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
Impact
When n8n-mcp runs in HTTP transport mode, incoming requests to the POST /mcp endpoint had their request metadata written to server logs regardless of the authentication outcome. In deployments where logs are collected, forwarded to external systems, or viewable outside the request trust boundary (shared log storage, SIEM pipelines, support/ops access), this can result in disclosure of:
- bearer tokens from the
Authorizationheader - per-tenant API keys from the
x-n8n-keyheader in multi-tenant setups - JSON-RPC request payloads sent to the MCP endpoint
Access control itself was not bypassed — unauthenticated requests were correctly rejected with 401 Unauthorized — but sensitive values from those rejected requests could still be persisted in logs.
Impact category: CWE-532 (Insertion of Sensitive Information into Log File).
Affected
Deployments running n8n-mcp v2.47.10 or earlier in HTTP transport mode (MCP_MODE=http). The stdio transport is not affected.
Patched
v2.47.11 and later.
- npm:
npx n8n-mcp@latest(or pin to>= 2.47.11) - Docker:
docker pull ghcr.io/czlonkowski/n8n-mcp:latest
Workarounds
If users cannot upgrade immediately:
- Restrict network access to the HTTP port (firewall, reverse proxy, or VPN) so only trusted clients can reach the endpoint.
- Switch to stdio transport (
MCP_MODE=stdio, the default for CLI invocation), which has no HTTP surface.
Credit
n8n-MCP thanks @S4nso (Organization / Jormungandr) for reporting this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | n8n-mcp | all versions | 2.47.11npm install n8n-mcp@2.47.11 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for n8n-mcp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update n8n-mcp to 2.47.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41495 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-41495 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-41495. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-41495 in your dependencies?
O3 Security finds CVE-2026-41495 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.