CVE-2026-71255: high-severity vulnerability in debevv nanoMODBUS
nanoMODBUS Client-Side Out-of-Bounds Write via object_length in recv_read_device_identification_res()
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.6epss 0.4%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
Affected products
debevv · nanoMODBUSRelated CVEs — debevv nanoMODBUS
In the same product, most dangerous first.
CVE-2026-71256CRITICALnanoMODBUS Client-Side Out-of-Bounds Read Leading to Wild-Pointer Write via object_idEPSS 0.6%CVE-2026-71254CRITICALnanoMODBUS Server-Side Out-of-Bounds Write in handle_read_file_record()EPSS 0.6%CVE-2026-54410HIGHnanoMODBUS Off-by-One Buffer Overflow in recv_msg_header() via Crafted MBAP Length FieldEPSS 0.5%