# CVE-2026-45582: czlonkowski n8n-mcp sensitive information leak in workflow telemetry

Source: https://junglewise.ai/threats/cve-2026-45582-czlonkowski-n8n-mcp-sensitive-information-leak-in-workflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-29. Updated: 2026-05-29  
License: CC BY 4.0 with a link back

CVE-2026-45582 · Severity: medium · CVSS 6.5 · Published 2026-05-29

n8n-MCP is a server that helps AI assistants interact with n8n automation workflows. A security flaw in the way it handles usage data (telemetry) meant that sensitive information, such as customer IDs, tenant names, and short security tokens, could be accidentally sent to the project's data collection backend. This could lead to the exposure of private configuration details or credentials to the software maintainers, contrary to the project's privacy policies.

Technologies: [n8n-mcp (npm)](https://junglewise.ai/threats/technologies/n8n-mcp). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-45582 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-45582 being exploited in the wild.

**How severe is CVE-2026-45582?** Medium severity, with a CVSS score of 6.5, published 29 May 2026.

**Which products and versions are affected?** n8n-mcp (npm) < 2.51.3, SEMVER:introduced=0,fixed=2.51.3.

**Is there a fix for CVE-2026-45582?** Yes. n8n-mcp (npm): upgrade to 2.51.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-45582 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-45582?** Check whether you run n8n-mcp (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- n8n-mcp (npm): upgrade to 2.51.3 or later

  ```sh
  npm install n8n-mcp@2.51.3
  ```


## Technical details

A vulnerability in the WorkflowSanitizer component of n8n-MCP allowed sensitive data to be included in telemetry sent to the project's Supabase backend. The sanitizer previously only replaced the hostname of 'url', 'endpoint', and 'webhook' fields with a generic placeholder, leaving the path and query strings intact. This resulted in the leakage of customer/tenant identifiers, signed request parameters, and short tokens (under 20 characters) that bypassed generic redaction logic. The issue was addressed in version 2.51.3 by implementing full redaction of these fields to '[REDACTED_URL]' and hardening the node schema validation.

## Affected products

- czlonkowski n8n-mcp < 2.51.3

## Identifiers

- CVE-2026-45582
- GHSA-f3rg-xqjj-cj9w

## Timeline

- 2026-05-11: patched: Fix committed and version 2.51.3 released.
- 2026-05-29: disclosed: Advisory published.

## References

- [https://github.com/czlonkowski/n8n-mcp/commit/6cf6fef653fcd6d598f2f356aac4754931c7329f](https://github.com/czlonkowski/n8n-mcp/commit/6cf6fef653fcd6d598f2f356aac4754931c7329f)
- [https://github.com/czlonkowski/n8n-mcp/pull/782](https://github.com/czlonkowski/n8n-mcp/pull/782)
- [https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.51.3](https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.51.3)
- [https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-f3rg-xqjj-cj9w](https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-f3rg-xqjj-cj9w)

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