A stack-based buffer overflow vulnerability (CVE-2026-5629) was discovered in Belkin F9K1015 router firmware version 1.00.10. The vulnerability exists in the formSetFirewall function within the /goform/formSetFirewall file, where manipulation of the webpage argument leads to buffer overflow. The vulnerability can be exploited remotely and public exploits are now available. The vendor was contacted about the disclosure but did not respond. This represents a critical security risk for affected Belkin routers as attackers can potentially execute arbitrary code remotely.