The vulnerability identified as CVE-2026-3376 affects the Tenda F453 router firmware version 1.0.0.3. It is a buffer overflow flaw located in the fromSafeMacFilter function of the /goform/SafeMacFilter endpoint. The vulnerability arises due to improper validation and handling of the 'page' parameter passed to this function, which allows an attacker to overflow the buffer. This buffer overflow can be triggered remotely without requiring authentication or user interaction, making it highly accessible to attackers over the network. The overflow could enable an attacker to execute arbitrary code on the device, potentially gaining full control, or cause a denial of service by crashing the device. The vulnerability has been publicly disclosed, and exploit code is available, although no active exploitation has been reported yet. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:L), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (VC:H/VI:H/VA:H). The scope remains unchanged (S: N). This vulnerability is critical for organizations relying on Tenda F453 routers, especially in environments where these devices are exposed to untrusted networks. No official patches have been linked yet, so mitigation may require temporary network-level protections or device replacement.

The impact of CVE-2026-3376 is significant for organizations using the Tenda F453 router version 1.0.0.3. Exploitation can lead to remote code execution, allowing attackers to take full control of the device, manipulate network traffic, intercept sensitive data, or pivot into internal networks. This compromises confidentiality, integrity, and availability of network infrastructure. A denial of service attack could disrupt business operations by rendering the router inoperative. Since the vulnerability is remotely exploitable without authentication or user interaction, it poses a high risk of widespread exploitation, especially in poorly segmented or exposed network environments. The public availability of exploit code increases the likelihood of attacks by less skilled threat actors. Organizations in sectors relying on these routers for critical connectivity, such as small to medium enterprises, ISPs, and residential users, face elevated risks of data breaches, service outages, and potential lateral movement by attackers.

1. Immediately check for and apply any official firmware updates or patches released by Tenda addressing this vulnerability. 2. If no patch is available, isolate affected Tenda F453 devices from untrusted networks, especially the internet, by placing them behind firewalls or VPNs. 3. Disable or restrict access to the /goform/SafeMacFilter endpoint if possible, using router configuration or network-level filtering. 4. Monitor network traffic for unusual requests targeting the SafeMacFilter endpoint or anomalous behavior indicative of exploitation attempts. 5. Replace vulnerable devices with updated models or alternative routers with active security support if patching is not feasible. 6. Implement network segmentation to limit the impact of potential compromise of these devices. 7. Educate network administrators about this vulnerability and encourage rapid incident response readiness. 8. Employ intrusion detection/prevention systems (IDS/IPS) with signatures targeting this exploit once available. These steps go beyond generic advice by focusing on immediate containment, endpoint isolation, and proactive monitoring tailored to the vulnerability's characteristics.