CVE-2026-54410
Severity CVSS v4.0:
HIGH
Type:
Unavailable / Other
Publication date:
14/06/2026
Last modified:
14/06/2026
Description
nanoMODBUS through v1.23.0 contains an off-by-one buffer overflow in the recv_msg_header() function of the Modbus/TCP server that allows remote unauthenticated attackers to write one attacker-controlled byte past the end of the 260-byte receive buffer by sending a crafted MBAP frame whose Length field is set to 255. The overflow corrupts the adjacent buffer-index field of the nanoMODBUS state structure, resulting in denial of service through invalid memory accesses and, on bare-metal and RTOS targets without memory protection, one-byte information disclosure and writes to unintended register addresses on the Write Multiple Registers (FC16) handler path.
Impact
Base Score 4.0
7.80
Severity 4.0
HIGH
Base Score 3.x
8.60
Severity 3.x
HIGH
Base Score 2.0
9.00
Severity 2.0
HIGH



