Ni8mare: Critical n8n vulnerability impacts ~60,000 instances
⚠️ A maximum-severity flaw dubbed Ni8mare (CVE-2026-21858) affects n8n and can allow unauthenticated remote attackers to take control of local instances by exploiting improper input validation in Form Submission triggers. Researchers say the bug enables secret exfiltration, session forgery, file injection, and command execution. Administrators should upgrade to n8n 1.121.0 immediately or restrict public webhook/form endpoints as a temporary mitigation.
