CVE-2019-5636: Beckhoff Twincat

High severity, CVSS 7.5. EPSS: 1.4% chance of exploitation in the next 30 days.

When a Beckhoff TwinCAT Runtime receives a malformed UDP packet, the ADS Discovery Service shuts down. Note that the TwinCAT devices are still performing as normal. This issue affects TwinCAT 2 version 2304 (and prior) and TwinCAT 3.1 version 4204.0 (and prior).

Affected products

• Beckhoff Twincat: version 2.0 only; version 3.1 only

Published 2019-11-21. Last modified 2026-06-17.