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Response snapshot Oct 27, 2026, 00:34 UTC

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VulnerabilityCVE-2026-42449

n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations.

n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. In versions 2.47.4 through 2.47.

At a glance

Exploited
Not known
Severity
8.5 High (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
2 independent sources

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-42449 (opens a new tab)

What happened

n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. In versions 2.47.4 through 2.47.13, the SDK embedder path (N8NDocumentationMCPServer constructor, getN8nApiClient(), and validateInstanceContext()), the synchronous URL validator in SSRFProtection.validateUrlSync() had no IPv6 checks. IPv4-mapped IPv6 addresses such as http://[::ffff:169.254.169.

254] bypassed the cloud-metadata, localhost, and private-IP range checks. An attacker able to supply an n8nApiUrl value could cause the server to issue HTTP requests to cloud metadata endpoints, RFC1918 private networks, or localhost services. Response bodies are returned to the caller (non-blind SSRF), and the n8nApiKey is forwarded in the x-n8n-api-key header to the attacker-controlled target.

Projects with deployments embedding n8n-mcp as an SDK using N8NDocumentationMCPServer or N8NMCPEngine with user-supplied InstanceContext are affected. The first-party HTTP server deployment was not primarily affected — it has a second async validator (validateWebhookUrl) that catches IPv6 addresses. This issue has been fixed in version 2.47.14.

If users are unable to upgrade immediately as a workaround they can validate URLs before passing to the SDK, restrict egress at the network layer, and reject user-controlled n8nApiUrl values.

Scores and how they were measured

CVSS base severity

8.5

Version 3.1As of

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-42449 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    Vendor advisory (via NVD references) (opens a new tab)

    The vendor advisory referenced by the CVE record, for affected versions and fixes.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  4. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  5. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 26). n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. (CVE-2026-42449). https://kevwire.com/record/CVE-2026-42449

MLA

"n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. (CVE-2026-42449)." KEVWire, 26 Oct. 2026, kevwire.com/record/CVE-2026-42449.

Chicago

KEVWire. "n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. (CVE-2026-42449)." Last modified October 26, 2026. https://kevwire.com/record/CVE-2026-42449.

Evidence summary (plain text)

n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. (May 7, 2026).
n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. In versions 2.47.4 through 2.47.13, the SDK embedder path (N8NDocumentationMCPServer constructor, getN8nApiClient(), and validateInstanceContext()), the synchronous URL validator in SSRFProtection.validateUrlSync() had no IPv6 checks. IPv4-mapped IPv6 addresses such as http://[::ffff:169.254.169.254] bypassed the cloud-metadata, localhost, and private-IP range checks. An attacker able to supply an n8nApiUrl value could cause the server to issue HTTP requests to cloud metadata endpoints, RFC1918 private networks, or localhost services. Response bodies are returned to the caller (non-blind SSRF), and the n8nApiKey is forwarded in the x-n8n-api-key header to the attacker-controlled target. Projects with deployments embedding n8n-mcp as an SDK using N8NDocumentationMCPServer or N8NMCPEngine with user-supplied InstanceContext are affected. The first-party HTTP server deployment was not primarily affected — it has a second async validator (validateWebhookUrl) that catches IPv6 addresses. This issue has been fixed in version 2.47.14. If users are unable to upgrade immediately as a workaround they can validate URLs before passing to the SDK, restrict egress at the network layer, and reject user-controlled n8nApiUrl values.
CVSS 8.5 (version 3.1; evidence as of Oct 26, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-42449).
Sources:
NVD CVE-2026-42449: https://nvd.nist.gov/vuln/detail/CVE-2026-42449
Vendor advisory (via NVD references): https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-56c3-vfp2-5qqj
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T20:05:59.720Z&lastModEndDate=2026-10-26T21:35:56.549Z&resultsPerPage=500&startIndex=1500
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T19:31:27.927Z&lastModEndDate=2026-10-26T21:05:56.246Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T19:01:15.495Z&lastModEndDate=2026-10-26T20:30:55.133Z&resultsPerPage=500&startIndex=500
Record ID: CVE-2026-42449.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 26, 2026, 21:35 UTC. Ingestion is not an independent editorial investigation.

NVD status: Analyzed. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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