CVE-2026-14818: path traversal vulnerability in the CLI command used to execute configuration files in Zyxel ATP series firmware versions from V4.32 through V5.42 Patch 1, USG FLEX series firmware versions from V4.50 through V5.42 Patch 1, USG FLEX 50(W) series firmware versions from V4.16 through V5.42 Patch 1, and USG20(W)-VPN series firmware versions from V4.16 through V5.42 Patch 1 could allow an authenticated attacker with administrator privileges to execute a crafted malicious configuration file on an affected device
This Zyxel advisory covers CVE-2026-14818 in ATP series firmware, USG FLEX series firmware and USG FLEX 50(W) series firmware.
- CVE-2026-14818
Key facts
- Vendor rating
- High, CVSS 7.2
- CISA KEV
- Not listed (catalogue checked )
- Affected
- through 5.42
- Source published
- Source revised
- Listed by VulniPulse
Compiled by VulniPulse from the linked sources. How records are collected and checked.
Affected products & platforms
Description
A path traversal vulnerability in the CLI command used to execute configuration files in Zyxel ATP series firmware versions from V4.32 through V5.42 Patch 1, USG FLEX series firmware versions from V4.50 through V5.42 Patch 1, USG FLEX 50(W) series firmware versions from V4.16 through V5.42 Patch 1, and USG20(W)-VPN series firmware versions from V4.16 through V5.42 Patch 1 could allow an authenticated attacker with administrator privileges to execute a crafted malicious configuration file on an affected device.
Text from the source record.
How to fix CVE-2026-14818
Vendor guidance
- A path traversal vulnerability in the CLI command used to execute configuration files in Zyxel ATP series firmware versions from V4.32 through V5.42 Patch 1, USG FLEX series firmware versions from V4.50 through V5.42 Patch 1, USG FLEX 50(W) series firmware versions from V4.16 through V5.42 Patch 1, and USG20(W)-VPN series firmware versions from V4.16 through V5.42 Patch 1 could allow an authenticated attacker with administrator privileges to execute a crafted malicious configuration file on an affected device.
End-of-life dates for Zyxel Firewalls (USG FLEX/ATP)
More Zyxel advisories
CVE-2024-11667Nov 27, 2024directory traversal vulnerability in the web management interface of Zyxel ATP seriesCVE-2026-76955Nov 3, 2026buffer overflow vulnerability in the zdp_wtp binary in Zyxel NWA110AX firmware versionsCVE-2026-107441Nov 3, 2026out-of-bounds write vulnerability in the CGI program of Zyxel GS1900-24E firmware versionsCVE-2026-12489Oct 20, 2026EX3501-T0 firmware privilege escalationCVE-2026-7273Jun 16, 2026stack-based buffer overflow vulnerability in the CGI program of Zyxel GS1900-48HPv2CVE-2026-3871Jun 2, 2026buffer overflow vulnerability in the UPnP DeletePortMapping command in Zyxel VMG4005-B50B
Get an email when Zyxel Firewalls (USG FLEX/ATP) publishes the next one.
See Zyxel Firewalls (USG FLEX/ATP)'s last 90 days of advisories first. Then choose one product with live alerts free for life, or a free month of real-time alerts on everything with the severity, the fixed version and the vendor's link (card needed, then US$15/month; we email you before the first charge).
iPhone and Android apps · New on the App Store
Monitor future Zyxel CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 34 official vendor sources and 160+ reviewed platform categories.
