The vulnerability is a stack‑based buffer overflow located in the Form_Logout function of the formLogout.htm component of the lighttpd web server on the Totolink NR1800X router. Manipulating the Host argument allows an attacker to overflow the stack, potentially causing arbitrary code execution. The CVSS score of 9.3 indicates a high severity for confidentiality, integrity, and availability, as an attacker can fully compromise the device.

The affected product is the Totolink NR1800X router running firmware version 9.1.0u.6279_B20210910. No other affected releases are listed in the CNA data, but any identical firmware build could be vulnerable.

The CVSS score of 9.3 confirms a critical risk level, while the EPSS score of less than 1% indicates that exploitation in the wild is currently uncommon. The vulnerability is exploitable remotely through the router’s web interface, and public exploit code has been released. Although the vulnerability is not listed in the CISA KEV catalog, its high severity and remote nature warrant prioritization in patch management and network hardening measures.