The TRENDnet TEW-755AP device up to version 20260702 contains a stack-based buffer overflow vulnerability in the ssi component, specifically in the /cgi-bin/wan.cgi file when processing the cameo.wan.wan_pppoe_password_00 argument. This vulnerability allows remote attackers with low privileges to cause a buffer overflow, potentially leading to complete compromise of confidentiality, integrity, and availability. The vulnerability is tracked as CVE-2026-76590 with a CVSS v3.1 score of 9.9, indicating critical impact. Public exploit code exists, but no active exploitation has been reported. No vendor advisory or patch information is currently available.

Successful exploitation of this vulnerability can lead to a stack-based buffer overflow, resulting in full compromise of the affected device's confidentiality, integrity, and availability. The vulnerability is remotely exploitable with low attack complexity and no user interaction required. Given the high CVSS score of 9.9, the impact is critical if exploited.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict remote access to the affected device's management interface to trusted networks only and monitor for any suspicious activity related to the /cgi-bin/wan.cgi endpoint. Avoid exposing the device's management interface to untrusted networks.