CVE-2026-42235
CriticalSummary
n8n is a workflow automation platform that prior to versions 1.123.32, 2.17.4, and 2.18.1 was vulnerable to an unauthenticated attacker registering a malicious OAuth client. After authorization by the victim, a malicious script could be executed in the victim's browser session.
Risk Assessment
An attacker could steal credentials, manipulate workflows, or escalate privileges, posing a serious security threat to the organization.
Recommendation
It is recommended to update n8n to versions 1.123.32, 2.17.4, or 2.18.1 to mitigate this vulnerability.
Original NVD description (English source)
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.