CVE-2018-7846: Schneider Electric Modicon m340 Firmware

Critical severity, CVSS 9.8. EPSS: 29.6% chance of exploitation in the next 30 days.

A CWE-501: Trust Boundary Violation vulnerability on connection to the Controller exists in all versions of the Modicon M580, Modicon M340, Modicon Quantum and Modicon Premium which could cause unauthorized access by conducting a brute force attack on Modbus protocol to the controller.

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.