CVE-2026-4906: Buffer Overflow in Tenda AC5 Firmware

The stack-based buffer overflow vulnerability in Tenda AC5 Firmware presents a significant security risk. An attacker could leverage this flaw to execute arbitrary code on the affected device, gaining complete control over the router. This could involve modifying router configurations, intercepting network traffic, launching attacks against internal network resources, or exfiltrating sensitive data. The remote nature of the exploit means an attacker does not need local access to the device, expanding the potential attack surface. Given the router's role as a gateway to a home or small business network, a successful compromise could have a wide-ranging impact, affecting all connected devices and services. This vulnerability shares similarities with other buffer overflow exploits that have led to full system compromise, highlighting the urgency of addressing it.

1. Reserved2026-03-26
2. Published2026-03-27
3. Modified2026-03-30
4. EPSS updated2026-04-03

Due to the lack of a patch at the time of writing, immediate mitigation steps are essential. Consider isolating the affected Tenda AC5 router from the internet by disabling WAN access or placing it behind a firewall. Implement strict firewall rules to restrict inbound traffic to the router, limiting exposure to potential attackers. Monitor router logs for any unusual activity or signs of exploitation. While not a complete solution, configuring a Web Application Firewall (WAF) in front of the router might offer some protection by filtering malicious requests. Regularly review and update router configurations to ensure they adhere to security best practices. After a firmware upgrade is released, confirm the vulnerability is resolved by attempting to reproduce the exploit scenario and verifying that it fails.