CVE-2019-5077: Wago Pfc 100 Firmware

Critical severity, CVSS 9.1. EPSS: 1.6% chance of exploitation in the next 30 days.

An exploitable denial-of-service vulnerability exists in the iocheckd service ‘’I/O-Chec’’ functionality of WAGO PFC 200 Firmware versions 03.01.07(13) and 03.00.39(12), and WAGO PFC 100 Firmware version 03.00.39(12). A specially crafted set of packets can cause a denial of service, resulting in the device entering an error state where it ceases all network communications. An attacker can send unauthenticated packets to trigger this vulnerability.

Affected products

• Wago Pfc 100 Firmware: version 03.00.39(12) only
• Wago Pfc 200 Firmware: version 03.00.39(12) only; version 03.01.07(13) only

Published 2019-12-18. Last modified 2026-06-17.