What is CVE-2026-42235?

CVE-2026-42235 is a critical-severity vulnerability in N8n, classified under Cross-site Scripting. CVSS score: 9.6/10. Published 2026-05-04.

How severe is CVE-2026-42235?

Critical severity. CVSS v3 base score is 9.6 out of 10.

XSS in N8n

CVE-2026-42235

n8n is an open source workflow automation platform. Prior to versions 1.123.32, 2.17.4, and 2.18.1, an unauthenticated attacker could register a malicious MCP OAuth client with a crafted client_name. If a victim user authorized the OAuth c…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.001 (23.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/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)

References

https://github.com/n8n-io/n8n/security/advisories/GHSA-537j-gqpc-p7fq (x_refsource_CONFIRM, Vendor Advisory)

Frequently asked questions

What is CVE-2026-42235?: CVE-2026-42235 is a critical-severity vulnerability in N8n, classified under Cross-site Scripting. CVSS score: 9.6/10. Published 2026-05-04.
How severe is CVE-2026-42235?: Critical severity. CVSS v3 base score is 9.6 out of 10.