KNX Association KNX Protocol Connection Authorization Option 1 Overly Restrictive Account Lockout Mechanism Vulnerability (CVE-2023-4346)
Severity: high · Patch status: unknown · Since 2026-07-15 · CVE-2023-4346
KNX Association KNX Protocol Connection Authorization Option 1 contains an overly restrictive account lockout mechanism vulnerability that could allow an attacker to purge all devices without additional security options enabled and set a BCU key to lock the device. CISA added CVE-2023-4346 to its Known Exploited Vulnerabilities catalog on Jul 15, 2026, which means attackers are exploiting it in the wild.
What to do
- Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
- US federal agencies must remediate by Jul 29, 2026 (BOD 22-01); treat that as the outer limit.
Sources
All live incidents on Threat Watch
