High severity · published Feb 5, 2026
CVE-2025-11730
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…
7.2
CVSS
1.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.4% · higher than 73% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AS
ATP series firmware · Zyxel
versions from V5.35 through V5.41 · source: vendor
UF
USG FLEX 50(W) series firmware · Zyxel
versions from V5.35 through V5.41 · source: vendor
UF
USG FLEX series firmware · Zyxel
versions from V5.35 through V5.41 · source: vendor
US
USG20(W)-VPN series firmware · Zyxel
versions from V5.35 through V5.41 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-11730
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-11730
www.zyxel.com
https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-post-authentication-command-injection-vulnerability-in-the-ddns-configuration-cli-command-of-zld-firewalls-02-05-2026
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