CVE-2026-3167 is a buffer overflow vulnerability identified in the Tenda F453 router firmware version 1.0.0.3. The vulnerability resides in the formWebTypeLibrary function of the /goform/webtypelibrary endpoint, which is part of the router's embedded HTTP server (httpd). Specifically, the flaw arises when the webSiteId parameter is manipulated with crafted input that exceeds the allocated buffer size, causing a buffer overflow. This condition can lead to arbitrary code execution or cause the device to crash, resulting in denial of service. The vulnerability can be exploited remotely without requiring authentication or user interaction, making it accessible to attackers over the network. The CVSS v4.0 base score of 8.7 reflects the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no privileges or user interaction needed. Although no confirmed exploits in the wild have been reported, a public exploit has been released, increasing the likelihood of exploitation. The vulnerability affects only the specific firmware version 1.0.0.3 of the Tenda F453 router, a device commonly used in home and small office networks. The lack of vendor patches at the time of disclosure necessitates immediate defensive measures to prevent exploitation.

The exploitation of CVE-2026-3167 can have severe consequences for organizations and individuals using the Tenda F453 router with the vulnerable firmware. Successful exploitation may allow attackers to execute arbitrary code remotely, potentially gaining full control over the device. This can lead to interception or manipulation of network traffic, unauthorized access to internal networks, and the establishment of persistent backdoors. Additionally, attackers could cause denial of service by crashing the device, disrupting internet connectivity and business operations. The compromise of network infrastructure devices like routers undermines the security perimeter, increasing the risk of lateral movement and further attacks within an organization’s network. Given the ease of exploitation and the public availability of an exploit, the threat is significant, especially for environments lacking proper network segmentation or firewall protections. The impact extends to confidentiality, integrity, and availability, making this a critical risk for affected deployments.

1. Monitor Tenda’s official channels for firmware updates addressing CVE-2026-3167 and apply patches immediately upon release. 2. Until patches are available, restrict access to the router’s management interface by limiting inbound connections to trusted IP addresses via firewall rules or network ACLs. 3. Disable remote management features on the Tenda F453 router if not strictly necessary to reduce exposure. 4. Employ network segmentation to isolate vulnerable devices from critical infrastructure and sensitive data. 5. Use intrusion detection and prevention systems (IDS/IPS) to monitor and block suspicious traffic targeting the /goform/webtypelibrary endpoint or unusual webSiteId parameter patterns. 6. Regularly audit router configurations and logs for signs of exploitation attempts or anomalous behavior. 7. Educate network administrators about this vulnerability and encourage proactive security hygiene, including changing default credentials and using strong authentication methods where possible. 8. Consider replacing outdated or unsupported devices with newer models that receive timely security updates.