Zyxel fixes 1 vulnerability

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[TLP:CLEAR] Zyxel fixes 1 vulnerability

Zyxel fixes 1 vulnerability in Zyxel ZLD (firewall firmware) in version 5.42. The specifically affected firewall series are ATP, USG FLEX, USG FLEX 50(W) and USG20(W)-VPN [1].

Zyxel ZLD (Firewall) - comand injection (CVE-2025-11730)

CVSS 7.2 (High)

Due to insufficient input sanitization in the command-line interface for dynamic DNS configuration, an authenticated remote attacker with administrator privileges can execute operating system commands via specially crafted input [1].

The vulnerability is present in products:

Zyxel ATP; >=5.35, <5.42
Zyxel USG FLEX; >=5.35, <5.42
Zyxel USG FLEX 50(W); >=5.35, <5.42
Zyxel USG20(W)-VPN; >=5.35, <5.42

CVSS: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

More information:

CVE-2025-11730 at cve.org, NVD
CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') at cwe.mitre.org

The vulnerability was publicly disclosed 5. 2. 2026.

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[TLP:CLEAR] Zyxel fixes 1 vulnerability

Zyxel ZLD (Firewall) - comand injection (CVE-2025-11730)

CVSS 7.2 (High)

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