A stack-based buffer overflow vulnerability (CVE-2026-5612) has been discovered in Belkin F9K1015 router firmware version 1.00.10. The vulnerability affects the formWlEncrypt function in /goform/formWlEncrypt file, allowing remote attackers to execute malicious code by manipulating the webpage argument. The exploit has been publicly disclosed and is available for use. Despite early notification, the vendor has not responded to the disclosure. This vulnerability poses significant risk as it can be exploited remotely without authentication.