CVE-2026-51677: n/a

This vulnerability arises from improper access control in the setUPnPCfg function of TOTOLINK T6 firmware 4.1.5cu.748_B20211015. An unauthenticated attacker can exploit this by sending a specially crafted POST request to the /cgi-bin/cstecgi.cgi endpoint, enabling them to change the state of the UPnP service. This can lead to unauthorized control over UPnP settings, potentially exposing the device to further attacks or misuse. The CVSS 3.1 base score is 9.1, reflecting network attack vector, low attack complexity, no privileges required, no user interaction, and high confidentiality and integrity impact.

Successful exploitation allows an unauthenticated attacker to modify the UPnP service state on the affected device, potentially enabling unauthorized network configuration changes. This compromises the confidentiality and integrity of the device's UPnP settings, which could facilitate further attacks or unauthorized access within the network environment. There is no indication of availability impact or known exploits in the wild at this time.

No patch or official fix information is currently available for this vulnerability. Since the device is not a cloud service, remediation depends on the vendor releasing an update. Users should monitor vendor advisories for updates. In the meantime, restricting network access to the device's management interfaces and disabling UPnP if not required may reduce exposure.