Report: Ultimate Guide: CVE-2026-42235 - n8n: XSS via MCP OAuth client

Report: Ultimate Guide: CVE-2026-42235 - n8n: XSS via MCP OAuth client

CVE ID :CVE-2026-42235 Published : May 4, 2026, 7:16 p.m. | 57 minutes ago Description :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 consent dialog and a second user subsequently revoked that access, a toast notification would render the injected script. Clicking the link would execute arbitrary JavaScript in the victim's authenticated n8n browser session, enabling credential and session token theft, workflow manipulation, or privilege escalation. This issue has been patched in versions 1.123.32, 2.17.4, and 2.18.1. Severity: 8.8 | HIGH Visit the link for more details, such as CVSS details, affected products, timeline, and more...

CVE Details

Severity
HIGH
Published
May 4, 2026
Impact: privilege escalation