CVE-2018-7843: Schneider Electric Modicon m340 Firmware

High severity, CVSS 7.5. EPSS: 3.3% chance of exploitation in the next 30 days.

A CWE-248: Uncaught Exception vulnerability exists in all versions of the Modicon M580, Modicon M340, Modicon Quantum, and Modicon Premium which could cause denial of service when reading memory blocks with an invalid data size or with an invalid data offset in the controller over Modbus.

Affected products

• Schneider Electric Modicon m340 Firmware: any version
• Schneider Electric Modicon m580 Firmware: any version
• Schneider Electric Modicon Premium Firmware: any version
• Schneider Electric Modicon Quantum Firmware: any version

Published 2019-05-22. Last modified 2026-06-17.