CVE-2026-2329: Grandstream GXP1600 VoIP Phones - Unauthenticated stack buffer overflow

An unauthenticated stack-based buffer overflow vulnerability exists in the HTTP API endpoint /cgi-bin/api.values.get. A remote attacker can leverage this vulnerability to achieve unauthenticated remote code execution (RCE) with root privileges on a target device. The vulnerability affects all six device models in the series: GXP1610, GXP1615, GXP1620, GXP1625, GXP1628, and GXP1630.