Unauthenticated Access Vulnerability in n8n Workflow Automation Platform
CVE-2026-42236

8.7HIGH

Key Information:

Vendor

N8n-io

Status
N8n
Vendor
CVE Published:
4 May 2026

What is CVE-2026-42236?

The n8n Workflow Automation Platform's MCP OAuth client registration endpoint is susceptible to unauthenticated requests. This vulnerability allows attackers to send large registration payloads, leading to potential resource exhaustion and making the n8n instance unavailable. Although MCP access can be toggled, this configuration does not limit client registrations. Users should upgrade to versions 1.123.32, 2.17.4, or 2.18.1 to mitigate this risk.

Affected Version(s)

n8n < 1.123.32 < 1.123.32

n8n >= 2.17.0, < 2.17.4 < 2.17.0, 2.17.4

n8n >= 2.18.0, < 2.18.1 < 2.18.0, 2.18.1

References

https://github.com/n8n-io/n8n/security/advisories/GHSA-49...
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CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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