CVE-2026-45582: n8n-MCP Workflow Telemetry Sanitizer Could Retain Vulnerability

MODERATE
Advisory Identifier: GHSA-f3rg-xqjj-cj9w
Share
CVSS 6.5
CWE-201
Published
Advisory Summary

CVE-2026-45582 is a MODERATE (CVSS 6.5) workflow telemetry sanitizer could retain vulnerability (CWE-201: Insertion of Sensitive Information Into Sent Data) affecting n8n-MCP libraries in the npm ecosystem. The issue involves workflow telemetry sanitizer could retain partial values from url-shaped node parameters. Remediation is available by upgrading affected packages to version 2.51.3.

CVE-2026-45582 at a Glance

CVE Identifier CVE-2026-45582
GHSA Identifier GHSA-f3rg-xqjj-cj9w
Severity MODERATE
CVSS v3.1 Base Score 6.5
CWE Classification CWE-201: Insertion of Sensitive Information Into Sent Data
Affected Product n8n-MCP
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 6.5

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

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

How to Fix CVE-2026-45582

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: 2.51.3 
npm install n8n-mcp@2.51.3
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-2026-45582, 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 2.51.3), 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-201: Insertion of Sensitive Information Into Sent Data, where the code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor. 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

## 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_DISABLED` - `TELEMETRY_DISABLED` - `DISABLE_TELEMETRY` ## Credit Reported by @u-ktdi.

CVE-2026-45582 Affected n8n-MCP Versions

1 component(s)
Fixed Versions:
2.51.3
Product / Package Ecosystem Affected Versions Fixed Version
n8n-mcp
npm/n8n-mcp
npm
< 2.51.3
2.51.3

References

GitHub Advisory / Wiki ADVISORY
https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-f3rg-xqjj-cj9w
NVD — CVE-2026-45582 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-45582
n8n-MCP Source Repository REPOSITORY
https://github.com/czlonkowski/n8n-mcp/pull/782
Security Fix Commit FIX COMMIT
https://github.com/czlonkowski/n8n-mcp/commit/6cf6fef653fcd6d598f2f356aac4754931c7329f
n8n-MCP Source Repository REPOSITORY
https://github.com/czlonkowski/n8n-mcp
n8n-MCP Release RELEASE
https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.51.3

Frequently Asked Questions

What is CVE-2026-45582?
CVE-2026-45582 is a security vulnerability in n8n-MCP involving Workflow telemetry sanitizer could retain partial values from URL-shaped node parameters under CWE-201: Insertion of Sensitive Information Into Sent Data.
Which n8n-MCP versions are affected?
Affected versions include releases prior to 2.51.3 across affected packages: n8n-mcp.
What version fixes CVE-2026-45582?
Upgrading to 2.51.3 (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 2.51.3. Upgrade your dependency to 2.51.3 or later.
What is the CVSS score of CVE-2026-45582?
CVE-2026-45582 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2026-45582?
CVE-2026-45582 is classified under CWE-201: Insertion of Sensitive Information Into Sent Data (The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.).
How can I check npm dependencies for CVE-2026-45582?
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-f3rg-xqjj-cj9w",
  "modified" : "2026-06-09T10:27:22Z",
  "published" : "2026-05-18T13:26:51Z",
  "aliases" : [ "CVE-2026-45582" ],
  "summary" : "n8n-MCP: Workflow telemetry sanitizer could retain partial values from URL-shaped node parameters",
  "details" : "## Summary\n\nIn 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`.\n\n## Impact\n\nOperators 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.\n\n## Patches\n\nFixed in **n8n-mcp `2.51.3`**. Upgrading is the recommended remediation.\n\n## Workarounds\n\nFor users who cannot upgrade immediately, disable anonymous telemetry by setting any of these environment variables to `true`:\n\n- `N8N_MCP_TELEMETRY_DISABLED`\n- `TELEMETRY_DISABLED`\n- `DISABLE_TELEMETRY`\n\n## Credit\n\nReported by @u-ktdi.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n-mcp"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.51.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-f3rg-xqjj-cj9w"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-45582"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/czlonkowski/n8n-mcp/pull/782"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/czlonkowski/n8n-mcp/commit/6cf6fef653fcd6d598f2f356aac4754931c7329f"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/czlonkowski/n8n-mcp"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.51.3"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-201" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-18T13:26:51Z",
    "nvd_published_at" : "2026-05-29T14:16:30Z"
  }
}