CVE-2026-41495: N8n mcp N8n-MCP Logs Sensitive Request Data Vulnerability

MODERATE
Advisory Identifier: GHSA-pfm2-2mhg-8wpx
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CVSS 5.3
CWE-532
Published
Advisory Summary

CVE-2026-41495 is a MODERATE (CVSS 5.3) n8n-mcp logs sensitive request data vulnerability (CWE-532: Insertion of Sensitive Information into Log File) affecting N8n mcp libraries in the npm ecosystem. The issue involves n8n-mcp logs sensitive request data on unauthorized /mcp requests. Remediation is available by upgrading affected packages to version 2.47.11.

CVE-2026-41495 at a Glance

CVE Identifier CVE-2026-41495
GHSA Identifier GHSA-pfm2-2mhg-8wpx
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-532: Insertion of Sensitive Information into Log File
Affected Product N8n mcp
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 5.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-41495

To remediate this vulnerability, upgrade all affected N8n mcp dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

n8n-mcp fixed: 2.47.11 
npm install n8n-mcp@2.47.11
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls n8n-mcp

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-41495, inspect your project dependencies using npm:

npm ls n8n-mcp

Analyze the terminal output to locate any version of N8n mcp in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.47.11), your application is affected.

Note: The npm ls n8n-mcp command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-532: Insertion of Sensitive Information into Log File, where the product writes sensitive information to a log file. In N8n mcp, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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 `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. 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](https://github.com/S4nso) (Organization / Jormungandr) for reporting this issue.

CVE-2026-41495 Affected N8n mcp Versions

1 component(s)
Fixed Versions:
2.47.11
Product / Package Ecosystem Affected Versions Fixed Version
n8n-mcp
npm/n8n-mcp
npm
< 2.47.11
2.47.11

References

GitHub Advisory / Wiki ADVISORY
https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-pfm2-2mhg-8wpx
NVD — CVE-2026-41495 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-41495
N8n mcp Source Repository REPOSITORY
https://github.com/czlonkowski/n8n-mcp
N8n mcp Release RELEASE
https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.47.11

Frequently Asked Questions

What is CVE-2026-41495?
CVE-2026-41495 is a security vulnerability in N8n mcp involving n8n-MCP Logs Sensitive Request Data on Unauthorized /mcp Requests under CWE-532: Insertion of Sensitive Information into Log File.
Which N8n mcp versions are affected?
Affected versions include releases prior to 2.47.11 across affected packages: n8n-mcp.
What version fixes CVE-2026-41495?
Upgrading to 2.47.11 (or the latest patched release for your respective branch) resolves the vulnerability.
Is n8n-mcp affected?
Yes, n8n-mcp is affected in releases prior to 2.47.11. Upgrade your dependency to 2.47.11 or later.
What is the CVSS score of CVE-2026-41495?
CVE-2026-41495 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2026-41495?
CVE-2026-41495 is classified under CWE-532: Insertion of Sensitive Information into Log File (The product writes sensitive information to a log file.).
How can I check npm dependencies for CVE-2026-41495?
Run the dependency tree command: 'npm ls n8n-mcp'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-pfm2-2mhg-8wpx",
  "modified" : "2026-05-13T13:33:57Z",
  "published" : "2026-04-23T14:31:46Z",
  "aliases" : [ "CVE-2026-41495" ],
  "summary" : "n8n-MCP Logs Sensitive Request Data on Unauthorized /mcp Requests",
  "details" : "### Impact\n\nWhen `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:\n\n- bearer tokens from the `Authorization` header\n- per-tenant API keys from the `x-n8n-key` header in multi-tenant setups\n- JSON-RPC request payloads sent to the MCP endpoint\n\nAccess 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.\n\nImpact category: **CWE-532** (Insertion of Sensitive Information into Log File).\n\n### Affected\n\nDeployments running n8n-mcp **v2.47.10 or earlier** in HTTP transport mode (`MCP_MODE=http`). The stdio transport is not affected.\n\n### Patched\n\n**v2.47.11** and later.\n\n- npm: `npx n8n-mcp@latest` (or pin to `>= 2.47.11`)\n- Docker: `docker pull ghcr.io/czlonkowski/n8n-mcp:latest`\n\n### Workarounds\n\nIf users cannot upgrade immediately:\n\n- Restrict network access to the HTTP port (firewall, reverse proxy, or VPN) so only trusted clients can reach the endpoint.\n- Switch to stdio transport (`MCP_MODE=stdio`, the default for CLI invocation), which has no HTTP surface.\n\n### Credit\n\nn8n-MCP thanks [@S4nso](https://github.com/S4nso) (Organization / Jormungandr) for reporting this issue.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n-mcp"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.47.11"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-pfm2-2mhg-8wpx"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-41495"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/czlonkowski/n8n-mcp"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.47.11"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-532" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-23T14:31:46Z",
    "nvd_published_at" : "2026-05-08T20:16:30Z"
  }
}