CVE-2026-54410 Details

A buffer overflow vulnerability has been identified in nanoMODBUS versions through 1.23.0, specifically within the Modbus/TCP server implementation. The issue arises in the recv_msg_header() function, where remote, unauthenticated attackers can exploit the vulnerability by sending a crafted MBAP frame with the Length field set to 255. This manipulation causes the server to write one byte beyond the end of a 260-byte receive buffer, corrupting adjacent memory and leading to invalid memory accesses. On bare-metal and RTOS targets without memory protection, this overflow could result in unauthorized information disclosure and unintended writes to register addresses during the handling of Write Multiple Registers (FC16) commands, causing a denial-of-service condition.