CVE-2026-3167 identifies a critical buffer overflow vulnerability in the Tenda F453 router firmware version 1.0.0.3. The vulnerability resides in the formWebTypeLibrary function of the HTTP daemon component, specifically in the handling of the webSiteId parameter within the /goform/webtypelibrary endpoint. Improper input validation or bounds checking allows an attacker to craft a malicious request that overflows the buffer, potentially overwriting adjacent memory. This flaw can be exploited remotely without authentication or user interaction, making it highly accessible for attackers. The buffer overflow could enable arbitrary code execution, allowing attackers to take full control of the device, disrupt network operations, or pivot into internal networks. The vulnerability has a CVSS 4.0 base score of 8.7, reflecting its high impact on confidentiality, integrity, and availability, combined with ease of exploitation. Although no active exploitation in the wild is reported, the public release of exploit code increases the urgency for mitigation. The lack of an official patch at the time of disclosure necessitates immediate defensive measures to reduce exposure.

The impact of CVE-2026-3167 is significant for organizations relying on Tenda F453 routers, particularly in environments where these devices serve as critical network gateways. Exploitation can lead to full device compromise, enabling attackers to intercept or manipulate network traffic, deploy malware, or establish persistent footholds within corporate or home networks. This can result in data breaches, service disruptions, and lateral movement to other internal systems. The vulnerability's remote and unauthenticated nature increases the attack surface, making it attractive for widespread exploitation campaigns. Given the router's role in network infrastructure, the availability of the device and the confidentiality of communications are at high risk. Organizations without timely mitigation may face operational downtime and reputational damage. The absence of known active exploitation currently provides a window for proactive defense, but the public exploit release elevates the threat level.

To mitigate CVE-2026-3167, organizations should first seek firmware updates or patches from Tenda as soon as they become available. In the absence of official patches, network administrators should implement strict access controls to limit exposure of the router's management interface, ideally restricting access to trusted internal networks only. Deploying network-level protections such as Web Application Firewalls (WAFs) or Intrusion Prevention Systems (IPS) with signatures targeting malformed requests to /goform/webtypelibrary can help detect and block exploit attempts. Disabling remote management features on the affected devices reduces the attack surface. Network segmentation should be enforced to isolate vulnerable devices from critical assets. Regular monitoring of router logs and network traffic for anomalous activity related to the webSiteId parameter or unexpected HTTP requests is recommended. Finally, organizations should consider replacing outdated or unsupported devices with more secure alternatives if patches are unavailable.