CVE-2026-42236 (GCVE-0-2026-42236)
Vulnerability from cvelistv5
Published
2026-05-04 18:38
Modified
2026-05-04 19:59
CWE
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Summary
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.
Impacted products
Vendor Product Version
n8n-io n8n Version: < 1.123.32
Version: >= 2.17.0, < 2.17.4
Version: >= 2.18.0, < 2.18.1
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Show details on NVD website


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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
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