CVE-2023-4346· NVD / CVE Program· CNA icscert

KNX devices that use KNX Connection Authorization and support Option 1 are, depending on the implementation, vulnerable to being locked and

Noroxi assessment

Priority: This week (action score 60/100)

CISA has confirmed exploitation in the wild (Jul 15, 2026). Remediation deadline for US federal agencies: Jul 29, 2026.
Probability of exploitation in the next 30 days: 1.2% (FIRST EPSS); higher than 70% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
According to the record, no fixed version is available yet.

Don’t wait for the next maintenance window. Until a fix is released, restrict access to the affected component and follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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.

HighCVSS 7.5 · v3.1KEVWeaponized No fix recorded

Published: Aug 29, 2023
Updated: Jul 16, 2026
EPSS: 1.2% · 70th percentile
CWE: CWE-645

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Action score

This week

Don’t wait for the next maintenance window.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 30 / 30 · Listed
EPSS: 0 / 30 · 1.2%

CISA SSVC decision

Exploitation: active
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 7.5
CNA · icscert: 7.5; agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Jul 15, 2026. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Jul 29, 2026.

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In CISA KEV: exploitation in the wild confirmed
Weaponized exploit exists
No fixed version yet

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
knx	connection authorization	cpe:2.3:a:knx:connection_authorization

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

knx connection authorizationall versions

Versions reported by the vendor

Affected version ranges reported by the assigning authority (icscert). Independent of NVD's CPE analysis and usually ahead of it.

KNX Association KNX Protocol Connection Authorization Option 1
- 0affected

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

PublishedAug 29, 2023
CISA KEVJul 15, 2026+1050 d
TodayOct 23, 2026+1151 d

EPSS, last 120 days+1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Felix Eberstallerreporter
Limes Securityfinder

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).