CVE-2026-3728 identifies a stack-based buffer overflow vulnerability in the Tenda F453 router firmware versions 1.0.0.3 and 1.If. The vulnerability resides in the fromSetCfm function, specifically in the handling of the funcname and funcpara1 parameters passed to the /goform/setcfm endpoint. Improper validation or bounds checking of these parameters allows an attacker to overwrite the stack memory, potentially corrupting the control flow of the application. This flaw can be triggered remotely over the network without requiring authentication or user interaction, making it highly exploitable. Successful exploitation could lead to arbitrary code execution with elevated privileges or cause the device to crash, resulting in denial of service. The vulnerability has been publicly disclosed, and while no confirmed exploits in the wild have been reported, the availability of exploit code increases the likelihood of attacks. The CVSS 4.0 base score is 8.7, indicating a high severity due to network attack vector, low attack complexity, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability. The affected product, Tenda F453, is a consumer-grade router commonly used in residential and small office environments, which may lack robust security monitoring, increasing exposure risk.

The impact of CVE-2026-3728 is significant for organizations and individuals using Tenda F453 routers. Exploitation can lead to full compromise of the affected device, allowing attackers to execute arbitrary code, potentially gaining control over the router’s firmware. This can result in interception or manipulation of network traffic, disruption of internet connectivity, and pivoting to internal networks for further attacks. The confidentiality of sensitive data passing through the router could be compromised, and the integrity of network communications undermined. Availability may also be affected if the device crashes or becomes unresponsive due to exploitation. Given the router’s role as a network gateway, successful attacks could facilitate broader network intrusions, data exfiltration, or deployment of malware. The lack of authentication and user interaction requirements lowers the barrier for attackers, increasing the threat to home users, small businesses, and possibly larger organizations relying on these devices.

To mitigate CVE-2026-3728, affected users and organizations should immediately check for firmware updates from Tenda addressing this vulnerability and apply them as soon as they become available. In the absence of official patches, network administrators should restrict access to the router’s management interfaces, especially the /goform/setcfm endpoint, by implementing firewall rules that limit access to trusted IP addresses only. Disabling remote management features or changing default management ports can reduce exposure. Network segmentation should be employed to isolate vulnerable devices from critical infrastructure. Monitoring network traffic for unusual requests targeting the /goform/setcfm endpoint can help detect exploitation attempts. Additionally, replacing affected devices with models from vendors with stronger security track records should be considered for long-term risk reduction. Regular security assessments and vulnerability scanning of network devices will help identify and remediate similar issues proactively.