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Vulnerability · Published May 8, 2026 · Assigned by GitHub_M

CVE-2026-41495n8n-MCP Logs Sensitive Request Data on Unauthorized /mcp Requests

Medium 5.3

In plain English

A medium-severity sensitive data in logs 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 17% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.3%top 82.8% 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 version 2.47.11, 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 Authorization header, per-tenant API keys from the, x-n8n-key header 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. This issue has been patched in version 2.47.11.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
npmn8n-mcp2.47.11GHSA-pfm2-2mhg-8wpx

Affected products (as reported)

VendorProductVersions
czlonkowski n8n-mcp < 2.47.11

Weakness: CWE-532 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References