The vulnerability CVE-2026-101039 affects FAST FAC1900R version 20190827_2.0.2. It is a stack-based buffer overflow in the copy_msg_element function within the devdiscover Service component. This flaw allows remote attackers to execute code or cause a denial of service by sending specially crafted input. The vulnerability has a CVSS 4.0 base score of 10.0, indicating critical severity with network attack vector, low attack complexity, no privileges or user interaction required, and high impacts on confidentiality, integrity, availability, scope, and safety. Public exploit code exists, and the vendor has not provided any response or patch.

Successful exploitation of this vulnerability can lead to remote code execution or denial of service on affected systems running FAST FAC1900R 20190827_2.0.2. The vulnerability impacts confidentiality, integrity, availability, scope, and safety at a high level, making it critical for affected deployments.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since the vendor has not responded and no patch links are available, users should consider applying network-level protections such as blocking or filtering traffic to the vulnerable service until an official fix is released.