Description

n8n is an open source workflow automation platform. Prior to versions 1.123.32, 2.17.4, and 2.18.1, the MCP OAuth client registration endpoint accepted unauthenticated requests and stored client data without adequate resource controls. An unauthenticated remote attacker could exhaust server memory resources by sending large registration payloads, rendering the n8n instance unavailable. The MCP enable/disable toggle gates MCP access but did not restrict client registrations, meaning the endpoint is reachable regardless of whether MCP access is enabled on the instance. This issue has been patched in versions 1.123.32, 2.17.4, and 2.18.1.

INFO

Published Date :

2026-05-04T18:38:51.626Z

Last Modified :

2026-05-04T19:59:24.621Z

Source :

GitHub_M
AFFECTED PRODUCTS

The following products are affected by CVE-2026-42236 vulnerability.

No data.

REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-42236.

CVSS Vulnerability Scoring System

Detailed values of each vector for above chart.
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability