Summary
Affected
Deployments running n8n-mcp v2.47.12 or earlier in HTTP transport mode (MCP_MODE=http). The stdio transport short-circuits the relevant log calls and is not affected in practice.
Patched
v2.47.13 and later.
- npm:
npx n8n-mcp@latest(or pin to>= 2.47.13) - Docker:
docker pull ghcr.io/czlonkowski/n8n-mcp:latest
The patch routes tool-call arguments through a metadata-only summarizer (summarizeToolCallArgs) that records type, top-level key names, and approximate size, never values. The same pattern was adopted earlier for HTTP request bodies in GHSA-pfm2-2mhg-8wpx.
Workarounds
If developers cannot upgrade immediately:
- Restrict access to the HTTP port (firewall, reverse proxy, or VPN) so only trusted clients can authenticate.
- Restrict access to server logs (no shared SIEM ingestion, no support read-only access) until the upgrade lands.
- Switch to stdio transport (
MCP_MODE=stdio, the default for CLI invocation), which has no HTTP surface and short-circuits the affected log calls.
Credit
n8n-MCP thanks @Mirr2 (Organization / Jormungandr) for reporting this issue.
Impact
When n8n-mcp runs in HTTP transport mode, authenticated MCP tools/call requests had their full arguments and JSON-RPC params written to server logs by the request dispatcher and several sibling code paths before any redaction. When a tool call carries credential material, most notably n8n_manage_credentials.data, the raw values can be persisted in logs.
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 and OAuth credentials sent through
n8n_manage_credentials - per-tenant API keys and webhook auth headers embedded in tool arguments
- arbitrary secret-bearing payloads passed to any MCP tool
The issue requires authentication (AUTH_TOKEN accepted by the server), so unauthenticated callers cannot trigger it; the runtime exposure is also reduced by an existing console-silencing layer in HTTP mode, but that layer is fragile and the values are still constructed and passed into the logger. The fix removes the leak at the source.
Impact category: CWE-532 (Insertion of Sensitive Information into Log File). CVSS 3.1 score: 4.3 Medium (AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).
CVE-2026-42282 has a CVSS score of 4.3 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.47.13); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-42282? CVE-2026-42282 is a medium-severity security vulnerability in n8n-mcp (npm), affecting versions < 2.47.13. It is fixed in 2.47.13.
- How severe is CVE-2026-42282? CVE-2026-42282 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of n8n-mcp are affected by CVE-2026-42282? n8n-mcp (npm) versions < 2.47.13 is affected.
- Is there a fix for CVE-2026-42282? Yes. CVE-2026-42282 is fixed in 2.47.13. Upgrade to this version or later.
- Is CVE-2026-42282 exploitable, and should I be worried? Whether CVE-2026-42282 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-42282 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-42282? Upgrade
n8n-mcpto 2.47.13 or later.