CVE-2026-3798 is a remote command injection vulnerability identified in the Comfast CF-AC100 wireless access point firmware version 2.6.0.8. The vulnerability resides in the CGI interface at /cgi-bin/mbox-config, specifically within the function sub_44AC14 that processes the ping_config section via the method=SET parameter. Improper input validation allows an attacker to inject arbitrary shell commands remotely without requiring authentication or user interaction. This flaw enables execution of commands with elevated privileges on the device, potentially compromising the device's integrity and availability. The vulnerability was responsibly disclosed to Comfast, but the vendor has not responded or released a patch. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:H - high privileges required, but the vector states PR:H which is contradictory; assuming the CVSS vector is correct, it requires high privileges), no user interaction (UI:N), and low impact on confidentiality, integrity, and availability (VC:L, VI:L, VA:L). The exploit code has been made public, increasing the risk of exploitation. The lack of vendor response and patch availability heightens the threat to organizations relying on this device. Attackers could leverage this vulnerability to execute arbitrary commands, disrupt network operations, or pivot to other network assets.

The primary impact of CVE-2026-3798 is unauthorized remote command execution on Comfast CF-AC100 devices, which can lead to full device compromise. This may allow attackers to alter device configurations, disrupt wireless network availability, intercept or manipulate network traffic, or use the device as a foothold for lateral movement within an organization’s network. The vulnerability affects the confidentiality, integrity, and availability of the device and potentially the broader network. Given the device’s role as a wireless access point, exploitation could impact wireless network users, degrade service quality, or facilitate further attacks against connected systems. The medium CVSS score reflects moderate severity, but the public availability of exploit code and lack of vendor patch increase the risk. Organizations with large deployments of Comfast CF-AC100 devices, especially in critical infrastructure or enterprise environments, face increased operational and security risks.

1. Immediately isolate Comfast CF-AC100 devices running firmware version 2.6.0.8 from untrusted networks to reduce exposure to remote attacks. 2. Implement strict network segmentation to limit access to management interfaces such as /cgi-bin/mbox-config. 3. Employ firewall rules or access control lists (ACLs) to restrict access to the device’s web management interface to trusted IP addresses only. 4. Monitor network traffic and device logs for unusual or suspicious requests targeting the ping_config endpoint. 5. Disable or restrict CGI interface access if possible until a vendor patch is available. 6. Consider replacing affected devices with alternative hardware from vendors with active security support. 7. Stay informed on vendor advisories and apply firmware updates promptly once a patch is released. 8. Conduct penetration testing and vulnerability scanning focused on wireless infrastructure to detect exploitation attempts. 9. Use intrusion detection/prevention systems (IDS/IPS) tuned to detect command injection patterns targeting Comfast devices. 10. Educate network administrators about this vulnerability and the importance of securing device management interfaces.