CVE-2023-4346: KNX Protocol Connection Authorization Option 1 Account Lockout Vulnerability

**CVE-2023-4346** is an overly restrictive account lockout vulnerability in KNX Connection Authorization Option 1 that lets an attacker with KNX bus access purge device configurations and set a new BCU key to permanently lock devices; CISA added it to the KEV on 2026-07-15, confirming real-world exploitation, and the report provides technical details, impact assessment, detection indicators, and remediation guidance (enable KNX IP/Data Secure, audit BCU keys, segment KNX traffic).