Path Traversal Vulnerability in Zyxel ATP and USG FLEX Series Firmware
CVE-2026-14818

7.2HIGH

Key Information:

Vendor

Zyxel
Status
Atp Series Firmware
Usg Flex Series Firmware
Usg Flex 50(w) Series Firmware
Usg20(w)-vpn Series Firmware
Vendor
CVE Published:
4 August 2026

What is CVE-2026-14818?

A path traversal vulnerability exists in the CLI command associated with executing configuration files on various Zyxel devices. This flaw potentially permits an authenticated attacker with administrator privileges to manipulate the execution of malicious configuration files. Specifically, the Zyxel ATP series firmware versions from V4.32 to V5.42 Patch 1, as well as multiple USG series firmware versions, are impacted, allowing possible unauthorized access to critical device functions.

Affected Version(s)

ATP series firmware from V4.32 through V5.42 Patch 1

USG FLEX 50(W) series firmware from V4.16 through V5.42 Patch 1

USG FLEX series firmware from V4.50 through V5.42 Patch 1

References

https://www.zyxel.com/global/en/support/security-advisori...
vendor-advisory

CVSS V3.1

Score:
7.2
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
High
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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