CVE-2025-11730

High

Description

A post‑authentication command injection vulnerability in the Dynamic DNS (DDNS) configuration CLI command in Zyxel ATP series firmware versions from V5.35 through V5.41, USG FLEX series firmware versions from V5.35 through V5.41, USG FLEX 50(W) series firmware versions from V5.35 through V5.41, and USG20(W)-VPN series firmware versions from V5.35 through V5.41 could allow an authenticated attacker with administrator privileges to execute operating system (OS) commands on an affected device by supplying a specially crafted string as an argument to the CLI command.

SeverityHigh
CVSS7.2
Exploit probability—
ProductUSG20(W)-VPN series firmware
PublishedFeb 5, 2026
First seenFeb 5, 2026

How to fix

Affected products

ProductAffected versionsFixed in
Zyxel USG20(W)-VPN series firmwareversions from V5.35 through V5.41—
Zyxel ATP series firmwareversions from V5.35 through V5.41—
Zyxel USG FLEX series firmwareversions from V5.35 through V5.41—
Zyxel USG FLEX 50(W) series firmwareversions from V5.35 through V5.41—

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