CVE-2025-40937: Siemens SIMATIC Cn 4100 Firmware

High severity, CVSS 8.8. EPSS: 0.6% chance of exploitation in the next 30 days.

A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected application do not properly validate input parameters in its REST API, resulting in improper handling of unexpected arguments. This could allow an authenticated attacker to execute arbitrary code with limited privileges.

Affected products

• Siemens SIMATIC Cn 4100 Firmware: before 4.0.1 (fixed in 4.0.1)

Published 2025-12-09. Last modified 2026-10-07.