CVE-2026-3169 identifies a critical buffer overflow vulnerability in the Tenda F453 router firmware version 1.0.0.3. The vulnerability resides in the fromSafeEmailFilter function of the HTTP daemon component, specifically in the handling of the 'page' parameter passed to the /goform/SafeEmailFilter endpoint. Improper input validation or bounds checking allows an attacker to overflow a buffer, potentially overwriting adjacent memory. This can lead to arbitrary code execution with elevated privileges on the device. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, making it highly dangerous. The CVSS 4.0 score of 8.7 reflects the ease of exploitation (network vector, low complexity), lack of required privileges or user interaction, and the high impact on confidentiality, integrity, and availability. Although no confirmed exploits in the wild have been reported, the public disclosure of the exploit code increases the likelihood of active exploitation attempts. The affected product, Tenda F453, is a widely deployed consumer and small office router, often used in home and SMB networks. Successful exploitation could allow attackers to gain persistent control over the device, intercept or manipulate network traffic, launch further attacks within the network, or cause denial of service. The absence of official patches or updates at the time of disclosure further exacerbates the risk.

The impact of CVE-2026-3169 is significant for organizations and individuals using the Tenda F453 router with firmware version 1.0.0.3. Exploitation can lead to full compromise of the router, enabling attackers to execute arbitrary code with elevated privileges. This can result in unauthorized access to internal networks, interception of sensitive data, manipulation or disruption of network traffic, and potential lateral movement to other connected devices. For small businesses and home users relying on this router for network security and connectivity, the vulnerability undermines the integrity and availability of their network infrastructure. Additionally, compromised routers can be leveraged as entry points for broader cyberattacks or as part of botnets for distributed denial-of-service (DDoS) campaigns. The lack of authentication and user interaction requirements lowers the barrier for attackers, increasing the likelihood of exploitation. The public availability of exploit code further raises the threat level, potentially leading to widespread attacks if mitigations are not applied promptly.

To mitigate CVE-2026-3169, affected users should immediately check for firmware updates from Tenda and apply any available patches addressing this vulnerability. In the absence of official patches, users should restrict access to the router's management interface by disabling remote administration and limiting access to trusted internal networks only. Network administrators should implement firewall rules to block external traffic to the /goform/SafeEmailFilter endpoint or the HTTP management interface altogether. Monitoring network logs for unusual or malformed requests targeting this endpoint can help detect exploitation attempts. Employing network segmentation to isolate critical systems from vulnerable routers can reduce potential lateral movement. Additionally, consider replacing the affected device with a router from a vendor with a strong security track record if patches are unavailable. Regularly updating router firmware and maintaining an inventory of network devices will aid in timely vulnerability management. Finally, educating users about the risks of exposing router management interfaces to the internet is essential to prevent exploitation.