CVE-2026-71255: Debevv Nanomodbus

High severity, CVSS 8.6. EPSS: 0.4% chance of exploitation in the next 30 days.

nanoMODBUS through v1.23.0 contains an out-of-bounds write in the Modbus client-side recv_read_device_identification_res function (FC 0x2B/MEI 0x0E, Read Device Identification) in nanomodbus.c. The server-supplied object_length field (0-246) is validated only against the remaining PDU size (res_size_left) and is never validated against the caller-supplied buffers_length parameter.

Affected products

• Debevv Nanomodbus: up to and including 1.23.0

Published 2026-08-05. Last modified 2026-08-26.