# CVE-2023-4346 — Knx Connection Authorization **CISA KEV** > As of 2026-07-16, CVE-2023-4346 is a HIGH-severity vulnerability in Knx Connection Authorization, CVSS v3.1 7.5, EPSS 0.9% (56.1th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-07-15), with a US federal remediation deadline of 2026-07-29. Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2023-4346, most recently “CISA Adds CVE-2026-46817 (Oracle E-Business Suite Payments Unauthenticated Takeover) and CVE-2023-4346 (KNX Protocol Account-Lockout) to KEV Catalog”. **Last updated:** 2026-07-16 ## What is CVE-2023-4346? 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. The record classifies CVE-2023-4346 under weakness class [CWE-645](https://cwe.mitre.org/data/definitions/645.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 1111 days ago. ## Severity and exploitation probability - **CVSS v3.1 base score:** 7.5 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **EPSS (FIRST):** 0.9% probability of exploitation in the next 30 days, higher than 56.1% of all scored CVEs - **CISA KEV:** Listed since 2026-07-15, federal remediation deadline 2026-07-29 - **Threadlinqs priority:** 9/10 — CISA KEV-listed, which Threadlinqs floors at 9 - **Published:** 2023-08-29, last modified 2026-07-16 ## Is CVE-2023-4346 being exploited? CISA added CVE-2023-4346 to the Known Exploited Vulnerabilities catalog on 2026-07-15, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-07-29 under BOD 22-01. It currently carries a trending score of 24 in the Threadlinqs vulnerability feed. ## Affected products and versions - **KNX Association**: KNX Protocol Connection Authorization Option 1 ## How to fix CVE-2023-4346 Because CVE-2023-4346 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-07-29. No vendor patch reference has been recorded for CVE-2023-4346 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise. ## Threat activity tracking CVE-2023-4346 1 tracked threat in the Threadlinqs corpus references CVE-2023-4346, either in the campaign’s CVE list or as an indicator on the campaign record. - [CISA Adds CVE-2026-46817 (Oracle E-Business Suite Payments Unauthenticated Takeover) and CVE-2023-4346 (KNX Protocol Account-Lockout) to KEV Catalog](https://intel.threadlinqs.com/threat/TL-2026-1395) — CRITICAL · 2026-07-16 ## Sources Enriched from CVE.org, NVD, FIRST EPSS, CISA KEV, GitHub Security Advisories. Last verified by Threadlinqs on 2026-07-28. This product uses the NVD API but is not endorsed or certified by the NVD. **Third-party advisory** - [cisa.gov — government resource](https://www.cisa.gov/news-events/ics-advisories/icsa-23-236-01) Canonical: https://intel.threadlinqs.com/cve/CVE-2023-4346 Full detection coverage and IOCs for threats exploiting CVE-2023-4346 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp