How severe is CVE-2023-4346?

CVE-2023-4346 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which products are affected by CVE-2023-4346?

CVE-2023-4346 affects the following products: knx connection authorization.

How do I patch CVE-2023-4346?

No patch has shipped for CVE-2023-4346 yet — track the knx connection authorization advisory for a fixed release and apply the workarounds below in the meantime.

How do I detect CVE-2023-4346 across my infrastructure?

Inventory every knx connection authorization deployment and check each version against the affected-products list above.

How do I mitigate CVE-2023-4346 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Is CVE-2023-4346 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-4346 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-4346?

CVE-2023-4346 has an EPSS (Exploit Prediction Scoring System) score of 1.3%, placing it in the 70th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

Is CVE-2023-4346 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2023-4346 (KNX Association KNX Protocol Connection Authorization Option 1 Overly Restrictive Account Lockout Mechanism Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-07-15. CISA required all US federal civilian agencies to remediate this vulnerability by 2026-07-29. The required action was: 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. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2023-4346?

CVE-2023-4346 is classified as CWE-645 (CWE-645). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2023-4346?

CVE-2023-4346 affects knx connection authorization. Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2023-4346 published, and has it been updated?

CVE-2023-4346 was published on August 29, 2023 and was last updated on July 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🛡️

CISA KEV · ACTIVELY EXPLOITED

HIGH severity

CVE-2023-4346 — Connection Authorization

HIGH

CVE-2023-4346 is a high-severity (CVSS 7.5) CWE-645 vulnerability in knx connection authorization. It is in CISA's Known Exploited Vulnerabilities catalog (added 2026-07-15) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.

KNX devices that use KNX Connection Authorization and support Option 1 are, depending on the implementation, vulnerable to being locked and users being unable to reset them to gain…

Published

Aug 29, 2023

Updated

Jul 16, 2026

Affected

1 product

Patched

See advisory

Exploits

None indexed

Exploitation data as of Oct 12, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2026-07-15. Federal agencies were required to remediate by 2026-07-29.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2023-4346.

EPSS Exploitation Probability

via FIRST.org ↗

1.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs70th percentile — riskier than 70% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2023-4346 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 386,684 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Description

KNX devices that use KNX Connection Authorization and support Option 1 are, depending on the implementation, vulnerable to being locked and users being unable to reset them to gain access to the device. The BCU key feature on the devices can be used to create a password for the device, but this password can often not be reset without entering the current password. If the device is configured to interface with a network, an attacker with access to that network could interface with the KNX installation, purge all devices without additional security options enabled, and set a BCU key, locking the device. Even if a device is not connected to a network, an attacker with physical access to the device could also exploit this vulnerability in the same way.

Affected Products

1 product · 1 configurations

Application

connection authorizationknx

all

Detection & mitigation playbook

Vendor / appliance

Detect
Inventory every knx connection authorization deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2023-4346 yet — track the knx connection authorization advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Frequently Asked Questions

O3 Security · Runtime Protection

Is CVE-2023-4346 being exploited in your environment?

Detect and block the exploit chain at execution, on systems you cannot patch yet.

Protect my workloads How runtime protection works