What is CVE-2026-42236?

CVE-2026-42236 is a high-severity vulnerability in N8n, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-05-04.

How severe is CVE-2026-42236?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in N8n

CVE-2026-42236

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…

EPSS: 0.002 (35.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

N8n — versions 2.18.0
N8n-io N8n — versions < 1.123.32, >= 2.17.0, < 2.17.4, >= 2.18.0, < 2.18.1

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

https://github.com/n8n-io/n8n/security/advisories/GHSA-49m9-pgww-9vq6 (x_refsource_CONFIRM, Vendor Advisory)

Frequently asked questions

What is CVE-2026-42236?: CVE-2026-42236 is a high-severity vulnerability in N8n, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-05-04.
How severe is CVE-2026-42236?: High severity. CVSS v3 base score is 7.5 out of 10.