CVE-2026-3380 identifies a critical buffer overflow vulnerability in the Tenda F453 router firmware version 1.0.0.3. The vulnerability resides in the function frmL7ImForm, specifically in the handling of the 'page' parameter passed to the /goform/L7Im endpoint. Improper validation or sanitization of this argument allows an attacker to overflow a buffer, which can corrupt memory and potentially enable arbitrary code execution. The attack vector is network-based and does not require authentication or user interaction, making it highly accessible to remote attackers. The CVSS 4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, with low attack complexity and no privileges required. The vulnerability is exploitable remotely, increasing the threat surface significantly. Although no confirmed exploits in the wild have been reported, the public availability of exploit code raises the likelihood of imminent attacks. The vulnerability affects only firmware version 1.0.0.3, and no official patches have been linked yet, indicating a window of exposure. This flaw could allow attackers to execute arbitrary code, disrupt device operation, or gain persistent control over the router, which is critical infrastructure in many networks.

The potential impact of CVE-2026-3380 is severe for organizations using the Tenda F453 router. Exploitation can lead to remote code execution, allowing attackers to take full control of the device, intercept or manipulate network traffic, and pivot into internal networks. This compromises confidentiality by exposing sensitive data, integrity by enabling unauthorized changes, and availability by causing denial of service or device crashes. Given the router’s role as a network gateway, a successful attack could disrupt business operations, leak confidential communications, and facilitate further attacks on connected systems. The lack of authentication and user interaction requirements lowers the barrier for attackers, increasing the risk of widespread exploitation. Enterprises, ISPs, and home users relying on this device are vulnerable, especially if the management interface is exposed to untrusted networks. The public disclosure of exploit code further escalates the threat, potentially leading to automated scanning and mass exploitation campaigns.

To mitigate CVE-2026-3380, organizations should immediately restrict access to the router’s management interface by implementing network segmentation and firewall rules to block unauthorized external access. Disable remote management features if not essential. Monitor network traffic for unusual requests targeting the /goform/L7Im endpoint or anomalous usage patterns. Apply any official firmware updates or patches from Tenda as soon as they become available. If patches are delayed, consider temporary mitigations such as deploying web application firewalls (WAFs) or intrusion prevention systems (IPS) to detect and block exploit attempts targeting the vulnerable parameter. Network administrators should also audit and update router configurations to minimize exposure and ensure strong administrative credentials. Regularly review threat intelligence feeds for new exploit developments and adjust defenses accordingly. For critical environments, consider replacing affected devices with models that have no known vulnerabilities or have received timely security updates.