CVE-2021-22699: Schneider Electric Modicon m241 Firmware

High severity, CVSS 7.5. EPSS: 1% chance of exploitation in the next 30 days.

Improper Input Validation vulnerability exists in Modicon M241/M251 logic controllers firmware prior to V5.1.9.1 that could cause denial of service when specific crafted requests are sent to the controller over HTTP.

Affected products

• Schneider Electric Modicon m241 Firmware: before 5.1.9.1 (fixed in 5.1.9.1)
• Schneider Electric Modicon m251 Firmware: before 5.1.9.1 (fixed in 5.1.9.1)

Published 2021-05-26. Last modified 2026-06-17.