CVE-2018-7856: Schneider Electric Modicon m340 Firmware

High severity, CVSS 7.5. EPSS: 1.6% 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 a possible denial of Service when writing invalid memory blocks to the controller over Modbus.

Affected products

• Schneider Electric Modicon m340 Firmware: before 3.10 (fixed in 3.10)
• Schneider Electric Modicon m580 Firmware: before 2.90 (fixed in 2.90)
• Schneider Electric Modicon Premium Firmware: affected versions not specified
• Schneider Electric Modicon Quantum Firmware: affected versions not specified

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