Exploited vulnerability · CISA KEV

Is CVE-2023-4346 exploited? Yes: in CISA KEV since 15 Jul 2026

Gociux · KNX Association KNX Protocol Connection Authorization Option 1 · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2023-4346, KNX Association KNX Protocol Connection Authorization Option 1 Overly Restrictive Account Lockout Mechanism Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 15 Jul 2026, 1051 days after it was published. It affects KNX Association KNX Protocol Connection Authorization Option 1. If you run it, CISA's required action is: 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.

What it is

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.

What to do

1. Check whether you run it. Look for KNX Protocol Connection Authorization Option 1 in your asset inventory, including appliances and cloud images. Stack check lists every exploited KNX Association CVE at once.
2. Apply the fix. 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.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 29 Aug 2023.
4. Get told next time. Email alerts when CISA adds a CVE for KNX Association.

References

• www.cisa.gov/news-events/ics-advisories/icsa-23-236-01
• nvd.nist.gov/vuln/detail/CVE-2023-4346

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in July 2026 · act-now radar.