What is CVE-2025-9133?

CVE-2025-9133 is a high-severity vulnerability in Zyxel Atp Series Firmware, classified under Missing Authorization. CVSS score: 8.1/10. Published 2025-10-21.

How severe is CVE-2025-9133?

High severity. CVSS v3 base score is 8.1 out of 10.

Auth bypass in Zyxel Atp Series Firmware

CVE-2025-9133

A missing authorization vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.40, USG FLEX series firmware versions from V4.50 through V5.40, USG FLEX 50(W) series firmware versions from V4.16 through V5.40, and USG20(W…

Vulnerability class: Broken Access Control

EPSS: 0.000 (15.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

Affected products

Zyxel Atp Series Firmware — versions versions from V4.32 through V5.40
Zyxel Usg20(w)-vpn Series Firmware — versions versions from V4.16 through V5.40
Zyxel Usg Flex 50(w) Series Firmware — versions versions from V4.16 through V5.40
Zyxel Usg Flex Series Firmware — versions versions from V4.50 through V5.40

Weakness classification (CWE)

CWE-862 — Missing Authorization

References

www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for… (vendor-advisory)

Frequently asked questions

What is CVE-2025-9133?: CVE-2025-9133 is a high-severity vulnerability in Zyxel Atp Series Firmware, classified under Missing Authorization. CVSS score: 8.1/10. Published 2025-10-21.
How severe is CVE-2025-9133?: High severity. CVSS v3 base score is 8.1 out of 10.