Vulnerability · Published Feb 5, 2026 · Assigned by Zyxel

CVE-2025-11730

High 7.2

In plain English

A high-severity OS command injection in ATP series firmware from Zyxel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.4% (higher than 73% of all known vulnerabilities).

Severity (CVSS 3.1)7.2High

Exploit odds (30 days)1.4%top 27.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
Zyxel	ATP series firmware	versions from V5.35 through V5.41
Zyxel	USG FLEX series firmware	versions from V5.35 through V5.41
Zyxel	USG FLEX 50(W) series firmware	versions from V5.35 through V5.41
Zyxel	USG20(W)-VPN series firmware	versions from V5.35 through V5.41

Weakness: CWE-78 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

References

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 vendor-advisory