CVE-2023-37926: Zyxel Zld

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

A buffer overflow vulnerability in the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLEX series firmware versions 4.50 through 5.37, USG FLEX 50(W) series firmware versions 4.16 through 5.37, USG20(W)-VPN series firmware versions 4.16 through 5.37, and VPN series firmware versions 4.30 through 5.37, could allow an authenticated local attacker to cause denial-of-service (DoS) conditions by executing the CLI command to dump system logs on an affected device.

Affected products

• Zyxel Zld: from 4.32, up to and including 5.37; from 4.50, up to and including 5.37; from 4.16, up to and including 5.37; from 4.30, up to and including 5.37

Published 2023-11-28. Last modified 2026-06-17.