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Fencer Vulns
high 8.1

CVE-2025-9133 json

A missing authorization vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.40, USG FLEX series firmware versions fro…

published 2025-10-21 12 mo ago modified 2026-10-18 21 d ago also EUVD-2025-35119

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
5.5%
EPSS 5.5% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

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)-VPN series firmware versions from V4.16 through V5.40 could allow a semi-authenticated attacker—who has completed only the first stage of the two-factor authentication (2FA) process—to view and download the system configuration from an affected device.

Patch / fix

  • zyxel zld 5.41

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
12 mo ago

Exploit prediction

5.46% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.1 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
  • Zyxel USG FLEX series firmware
  • Zyxel USG FLEX 50(W) series firmware
  • Zyxel USG20(W)-VPN series firmware

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.