Cybersecurity researchers have disclosed details of yet another maximum-severity security flaw in n8n, a popular workflow automation platform, that allows an unauthenticated remote attacker to gain complete control over susceptible instances. The vulnerability, tracked as CVE-2026-21858 (CVSS score: 10.0), has been codenamed Ni8mare by Cyera Research Labs. Security researcher Dor Attias has been