CVE-2023-37927: Zyxel NAS326 Firmware

High severity, CVSS 8.8. EPSS: 1.8% chance of exploitation in the next 30 days.

The improper neutralization of special elements in the CGI program of the Zyxel NAS326 firmware version V5.21(AAZF.14)C0 and NAS542 firmware version V5.21(ABAG.11)C0 could allow an authenticated attacker to execute some operating system (OS) commands by sending a crafted URL to a vulnerable device.

Affected products

• Zyxel NAS326 Firmware: up to and including 5.21\(aazf.14\)c0
• Zyxel NAS542 Firmware: up to and including 5.21\(abag.11\)c0

Published 2023-11-30. Last modified 2026-06-17.