A remote command injection vulnerability (CVE-2026-7548) was discovered in Totolink NR1800X router firmware version 9.1.0u.6279_B20210910. The vulnerability affects the sub_41A68C function in /cgi-bin/cstecgi.cgi file. Attackers can exploit this by manipulating the setUssd argument to achieve command injection. The vulnerability can be exploited remotely and public exploits are now available. This presents a high risk to affected devices as it allows remote code execution on network infrastructure equipment.