CVE-2026-3044 identifies a critical security vulnerability in the Tenda AC8 router firmware version 16.03.34.06. The vulnerability is a stack-based buffer overflow located in the webCgiGetUploadFile function of the HTTP daemon service, specifically in the /cgi-bin/UploadCfg endpoint. The root cause is improper handling of the 'boundary' argument, which can be manipulated remotely by an attacker to overflow the stack buffer. This overflow can corrupt memory, potentially allowing arbitrary code execution or causing the device to crash, resulting in denial of service. The attack vector is network-based, requiring no authentication or user interaction, which significantly lowers the barrier for exploitation. The CVSS v4.0 score is 8.7 (high), reflecting the ease of remote exploitation and the severe impact on confidentiality, integrity, and availability. Although no known exploits are currently active in the wild, the public disclosure of the vulnerability details increases the likelihood of future exploitation attempts. The affected product, Tenda AC8, is a consumer and small office router widely used in various regions, making the vulnerability a significant concern for network security. No official patches or mitigation links have been provided yet, emphasizing the need for proactive defensive measures.

The impact of CVE-2026-3044 is substantial for organizations and individuals relying on Tenda AC8 routers. Exploitation can lead to remote code execution, allowing attackers to gain control over the device, intercept or manipulate network traffic, and potentially pivot to internal networks. This compromises confidentiality and integrity of data traversing the router. Additionally, successful exploitation can cause denial of service by crashing the device, disrupting network availability. For enterprises and service providers using these routers as part of their infrastructure, this vulnerability poses risks of network breaches, data leakage, and operational downtime. The lack of authentication and user interaction requirements increases the threat level, as attackers can scan and exploit vulnerable devices en masse. The public disclosure of the vulnerability details further elevates the risk of automated exploit development and widespread attacks, potentially affecting millions of devices globally.

1. Immediate mitigation should include isolating Tenda AC8 devices from untrusted networks and restricting access to the /cgi-bin/UploadCfg endpoint via firewall rules or network segmentation. 2. Monitor network traffic for unusual requests targeting the vulnerable CGI endpoint, using intrusion detection systems with custom signatures for the boundary parameter manipulation. 3. Disable remote management features on the router if not required, reducing the attack surface. 4. Regularly check for firmware updates from Tenda and apply patches promptly once available. 5. If patches are unavailable, consider replacing affected devices with models from vendors with active security support. 6. Employ network-level protections such as web application firewalls (WAFs) or reverse proxies to filter malicious HTTP requests targeting the router. 7. Conduct internal network scans to identify all Tenda AC8 devices and assess exposure. 8. Educate network administrators about this vulnerability and encourage proactive monitoring and incident response readiness.