A vulnerability was found in TOTOLINK NR1800X 9.1.0u.6681_B20230703. Impacted is the function setUploadSetting of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument FileName results in stack-based buffer overflow. The attack can be executed remotely. The exploit has been made public and could be used.

A stack-based buffer overflow vulnerability has been identified in TOTOLINK NR1800X firmware version 9.1.0u.6681_B20230703. The vulnerability exists in the setUploadSetting function within the /cgi-bin/cstecgi.cgi file. Attackers can exploit this by manipulating the FileName argument to trigger a stack-based buffer overflow. The attack vector is remote, requiring no physical access to the device. A public exploit has already been released, increasing the risk of active exploitation. TOTOLINK NR1800X is a network router/modem device, making this vulnerability particularly impactful for network infrastructure security. The vulnerability has been assigned CVE-2026-82616 and is tracked in VulDB. Organizations using the affected firmware version should monitor for patches from TOTOLINK. The public availability of the exploit significantly raises the urgency of remediation.