Zyxel Patches Stack-Based Buffer Overflow in GS1900 Switches (CVE-2026-7273)

Zyxel has released firmware updates to address a stack-based buffer overflow in its GS1900 series switches, tracked as CVE-2026-7273 and scored 8.8 (CVSS). The issue impacts the GS1900-8, GS1900-24, and GS1900-48HPv2, among other GS1900 models running firmware version 2.90 or earlier, and could allow a LAN-based, unauthenticated attacker to execute commands and potentially take control of the device. Because affected switches are often central to network operations, patching promptly is important to reduce the risk of intrusion and lateral movement.