Belkin F9K1015 Setting formSetSystemSettings stack-based overflow

Successful exploitation of CVE-2026-5628 allows an attacker to execute arbitrary code on the vulnerable Belkin F9K1015 router. This could lead to complete compromise of the device, enabling attackers to intercept network traffic, modify router configurations, launch attacks against other devices on the network, or exfiltrate sensitive data. Given the router's role in network connectivity, a successful attack could have a significant impact on the confidentiality, integrity, and availability of the entire network. The public disclosure of the exploit increases the likelihood of widespread exploitation.

Small to medium-sized businesses and home users relying on the Belkin F9K1015 router are at risk. Organizations with legacy Belkin router deployments or those lacking robust network monitoring capabilities are particularly vulnerable. Shared hosting environments where the router is managed by the hosting provider also present a risk.

• linux / server:

journalctl -u belkin-f9k1015 | grep -i 'webpage' -i 'buffer overflow'

• generic web:

curl -I http://<router_ip>/goform/formSetSystemSettings?webpage=<malicious_input>

Inspect the response headers and body for any errors or unusual behavior. • linux / server:

lsof -i :80 | grep belkin

Check for unusual processes listening on port 80 that might indicate compromise.

1. 2026-04-06Disclosure

   disclosure

1. 予約済み2026-04-05
2. 公開日2026-04-06
3. EPSS 更新日2026-04-13

The primary mitigation for CVE-2026-5628 is to upgrade the Belkin F9K1015 router to a patched firmware version. Unfortunately, no patched firmware has been released by Belkin. As a temporary workaround, consider implementing strict firewall rules to restrict access to the /goform/formSetSystemSettings endpoint from untrusted sources. Monitor router logs for any unusual activity or attempts to exploit the vulnerability. While a WAF might offer some protection, its effectiveness against this specific buffer overflow is uncertain. After attempting any configuration changes, verify the router's functionality and security posture by attempting to access the management interface and confirming that unauthorized access is prevented.