Three chained vulnerabilities in Ubiquiti UniFi OS (path traversal, improper access control, improper input validation) are confirmed active with a public proof-of-concept achieving unauthenticated root shell access via a single chained HTTP request. CISA has confirmed active exploitation. All UniFi OS versions listed as affected in Ubiquiti Security Advisory Bulletin SAB-064 are vulnerable. Organizations running UniFi Network controllers, UniFi OS Consoles, or UniFi Dream Machines in enterprise or campus network management roles face immediate risk of complete management plane compromise.