Grandstream GXP1600 VoIP Phones Exposed to Unauthenticated Remote Code Execution
Feb 18, 2026
Network Security / Enterprise Security
Cybersecurity researchers have disclosed a critical security flaw in the Grandstream GXP1600 series of VoIP phones that could allow an attacker to seize control of susceptible devices. The vulnerability, tracked as CVE-2026-2329 , carries a CVSS score of 9.3 out of a maximum of 10.0. It has been described as a case of unauthenticated stack-based buffer overflow that could result in remote code execution. "A remote attacker can leverage CVE-2026-2329 to achieve unauthenticated remote code execution (RCE) with root privileges on a target device," Rapid7 researcher Stephen Fewer, who discovered and reported the bug on January 6, 2026, said . According to the cybersecurity company, the issue is rooted in the device's web-based API service ("/cgi-bin/api.values.get") and is accessible in a default configuration without requiring authentication. This endpoint is designed to fetch one or more configuration values from the phone, such as the firmware version number...
