Critical UniFi OS bug lets hackers gain root without authentication

Three patched vulnerabilities in Ubiquiti UniFi OS Server versions 5.0.6 and earlier can be chained for unauthenticated remote code execution with root privileges. Tracked as CVE-2026-34908, CVE-2026-34909, and CVE-2026-34910, the flaws allow authentication bypass via URI normalization mismatch and command injection. Bishop Fox researchers demonstrated the full attack path requires no credentials or user interaction.