Zyxel Vulnerabilities and Affected Products
Vulnerabilities associated with ATP series firmware.
Products
Clear product- USG FLEX series firmware51 vulnerabilities
- ATP series firmware49 vulnerabilities
- VPN series firmware37 vulnerabilities
- USG FLEX 50(W) series firmware28 vulnerabilities
- USG20(W)-VPN series firmware28 vulnerabilities
- NAS326 firmware15 vulnerabilities
- NAS542 firmware14 vulnerabilities
- USG FLEX 50(W) firmware11 vulnerabilities
- nas326_firmware9 vulnerabilities
- nas542_firmware9 vulnerabilities
- usg_flex_50w_firmware9 vulnerabilities
- USG/ZyWALL series firmware8 vulnerabilities
- USG20(W)-VPN firmware8 vulnerabilities
- VMG8825-T50K firmware8 vulnerabilities
- VMG3625-T50B firmware7 vulnerabilities
- WAC500 firmware7 vulnerabilities
- atp800_firmware6 vulnerabilities
- usg_flex_700h_firmware6 vulnerabilities
- Multiple Firewalls5 vulnerabilities
- NBG-418N v2 firmware5 vulnerabilities
- NR7101 firmware5 vulnerabilities
- NWA50AX firmware5 vulnerabilities
- usg_flex_firmware5 vulnerabilities
- WBE660S firmware5 vulnerabilities
- ZyWALL/USG series firmware5 vulnerabilities
| Vulnerability | Title and context | CVSS | EPSS | PoCs | Signals | STIX action |
|---|---|---|---|---|---|---|
CVE-2026-14818HIGH | Generated title:Zyxel ATP and USG FLEX Series Firmware Path Traversal VulnerabilityA 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 a… CWE-22Aug 4, 2026 | CVSS7.2v3.1 | EPSS0.359% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2025-11730HIGH | Generated title:Zyxel ATP/USG FLEX/USG20(W)-VPN Series Firmware Post-Authentication OS Command Injection in DDNS CLIA 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 su… CWE-78Feb 5, 2026 | CVSS7.2v3.1 | EPSS1.35% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2025-9133HIGH | 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. CWE-862Oct 21, 2025 | CVSS8.1v3.1 | EPSS5.44% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2025-8078HIGH | A post-authentication command injection 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 an authenticated attacker with administrator privileges to execute operating system (OS) commands on the affected device by passing a crafted string as an argument to a CLI comm… CWE-78Oct 21, 2025 | CVSS7.2v3.1 | EPSS1.48% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2024-11667HIGH | Zyxel Multiple Firewalls Path Traversal VulnerabilityA directory traversal vulnerability in the web management interface of Zyxel ATP series firmware versions V5.00 through V5.38, USG FLEX series firmware versions V5.00 through V5.38, USG FLEX 50(W) series firmware versions V5.10 through V5.38, and USG20(W)-VPN series firmware versions V5.10 through V5.38 could allow an attacker to download or upload files via a crafted URL. CWE-22Nov 27, 2024 | CVSS7.5v3.1 | EPSS3.02% | PoCs0 | SignalsListed in CISA KEVKnown ransomware useNo Nuclei templates | STIX |
CVE-2024-42061MEDIUM | A reflected cross-site scripting (XSS) vulnerability in the CGI program "dynamic_script.cgi" of Zyxel ATP series firmware versions from V4.32 through V5.38, USG FLEX series firmware versions from V4.50 through V5.38, USG FLEX 50(W) series firmware versions from V4.16 through V5.38, and USG20(W)-VPN series firmware versions from V4.16 through V5.38 could allow an attacker to trick a user into visiting a crafted URL with the XSS payload. The attacker could obtain browser-based information if the m… CWE-79Sep 3, 2024 | CVSS6.1v3.1 | EPSS0.312% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2024-42060HIGH | A post-authentication command injection vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.38, USG FLEX series firmware versions from V4.50 through V5.38, USG FLEX 50(W) series firmware versions from V4.16 through V5.38, and USG20(W)-VPN series firmware versions from V4.16 through V5.38 could allow an authenticated attacker with administrator privileges to execute some OS commands on an affected device by uploading a crafted internal user agreement file to the vulnerable d… CWE-78Sep 3, 2024 | CVSS7.2v3.1 | EPSS1.34% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2024-42059HIGH | A post-authentication command injection vulnerability in Zyxel ATP series firmware versions from V5.00 through V5.38, USG FLEX series firmware versions from V5.00 through V5.38, USG FLEX 50(W) series firmware versions from V5.00 through V5.38, and USG20(W)-VPN series firmware versions from V5.00 through V5.38 could allow an authenticated attacker with administrator privileges to execute some OS commands on an affected device by uploading a crafted compressed language file via FTP. CWE-78Sep 3, 2024 | CVSS7.2v3.1 | EPSS1.34% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2024-42058HIGH | A null pointer dereference vulnerability in Zyxel ATP series firmware versions from V4.32 through V5.38, USG FLEX series firmware versions from V4.50 through V5.38, USG FLEX 50(W) series firmware versions from V5.20 through V5.38, and USG20(W)-VPN series firmware versions from V5.20 through V5.38 could allow an unauthenticated attacker to cause DoS conditions by sending crafted packets to a vulnerable device. CWE-476Sep 3, 2024 | CVSS7.5v3.1 | EPSS0.621% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2024-42057HIGH | Zyxel zld Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')A command injection vulnerability in the IPSec VPN feature of Zyxel ATP series firmware versions from V4.32 through V5.38, USG FLEX series firmware versions from V4.50 through V5.38, USG FLEX 50(W) series firmware versions from V4.16 through V5.38, and USG20(W)-VPN series firmware versions from V4.16 through V5.38 could allow an unauthenticated attacker to execute some OS commands on an affected device by sending a crafted username to the vulnerable device. Note that this attack could be success… CWE-78Sep 3, 2024 | CVSS8.1v3.1 | EPSS1.32% | PoCs0 | SignalsNot listed in CISA KEVKnown ransomware useNo Nuclei templates | STIX |
CVE-2024-7203HIGH | A post-authentication command injection vulnerability in Zyxel ATP series firmware versions from V4.60 through V5.38 and USG FLEX series firmware versions from V4.60 through V5.38 could allow an authenticated attacker with administrator privileges to execute some operating system (OS) commands on an affected device by executing a crafted CLI command. CWE-78Sep 3, 2024 | CVSS7.2v3.1 | EPSS1.34% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2024-6343MEDIUM | A buffer overflow vulnerability in the CGI program of Zyxel ATP series firmware versions from V4.32 through V5.38, USG FLEX series firmware versions from V4.50 through V5.38, USG FLEX 50(W) series firmware versions from V4.16 through V5.38, and USG20(W)-VPN series firmware versions from V4.16 through V5.38 could allow an authenticated attacker with administrator privileges to cause denial of service (DoS) conditions by sending a crafted HTTP request to a vulnerable device. CWE-120Sep 3, 2024 | CVSS4.9v3.1 | EPSS0.605% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2023-6764HIGH | A format string vulnerability in a function of the IPSec VPN feature in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1, USG FLEX series firmware versions from 4.50 through 5.37 Patch 1, USG FLEX 50(W) series firmware versions from 4.16 through 5.37 Patch 1, and USG20(W)-VPN series firmware versions from 4.16 through 5.37 Patch 1 could allow an attacker to achieve unauthorized remote code execution by sending a sequence of specially crafted payloads containing an invalid pointe… CWE-134Feb 20, 2024 | CVSS8.1v3.1 | EPSS0.889% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2023-6399MEDIUM | A format string vulnerability in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1, USG FLEX series firmware versions from 4.50 through 5.37 Patch 1, USG FLEX 50(W) series firmware versions from 4.16 through 5.37 Patch 1, USG20(W)-VPN series firmware versions from 4.16 through 5.37 Patch 1, and USG FLEX H series firmware versions from 1.10 through 1.10 Patch 1 could allow an authenticated IPSec VPN user to cause DoS conditions against the “deviceid” daemon by sending a crafted ho… CWE-134Feb 20, 2024 | CVSS5.7v3.1 | EPSS0.649% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2023-6398HIGH | A post-authentication command injection vulnerability in the file upload binary in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1, USG FLEX series firmware versions from 4.50 through 5.37 Patch 1, USG FLEX 50(W) series firmware versions from 4.16 through 5.37 Patch 1, USG20(W)-VPN series firmware versions from 4.16 through 5.37 Patch 1, USG FLEX H series firmware versions from 1.10 through 1.10 Patch 1, NWA50AX firmware versions through 6.29(ABYW.3), WAC500 firmware version… CWE-78Feb 20, 2024 | CVSS7.2v3.1 | EPSS1.33% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2023-6397MEDIUM | A null pointer dereference vulnerability in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1 and USG FLEX series firmware versions from 4.50 through 5.37 Patch 1 could allow a LAN-based attacker to cause denial-of-service (DoS) conditions by downloading a crafted RAR compressed file onto a LAN-side host if the firewall has the “Anti-Malware” feature enabled. CWE-476Feb 20, 2024 | CVSS6.5v3.1 | EPSS0.3% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2023-5797MEDIUM | An improper privilege management vulnerability in the debug CLI command of the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLEX series firmware versions 4.50 through 5.37, USG FLEX 50(W) series firmware versions 4.16 through 5.37, USG20(W)-VPN series firmware versions 4.16 through 5.37, VPN series firmware versions 4.30 through 5.37, NWA50AX firmware version 6.29(ABYW.2), WAC500 firmware version 6.65(ABVS.1), WAX300H firmware version 6.60(ACHF.1), and WBE660S firmware version 6.65(… CWE-269Nov 28, 2023 | CVSS5.5v3.1 | EPSS0.212% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2023-5650MEDIUM | An improper privilege management vulnerability in the ZySH of the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLEX series firmware versions 4.50 through 5.37, USG FLEX 50(W) series firmware versions 4.16 through 5.37, USG20(W)-VPN series firmware versions 4.16 through 5.37, and VPN series firmware versions 4.30 through 5.37, could allow an authenticated local attacker to modify the URL of the registration page in the web GUI of an affected device. CWE-269Nov 28, 2023 | CVSS5.5v3.1 | EPSS0.214% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2023-4398HIGH | An integer overflow vulnerability in the source code of the QuickSec IPSec toolkit used in the VPN feature of the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLEX series firmware versions 4.50 through 5.37, USG FLEX 50(W) series firmware versions 4.16 through 5.37, USG20(W)-VPN series firmware versions 4.16 through 5.37, and VPN series firmware versions 4.30 through 5.37, could allow an unauthenticated attacker to cause denial-of-service (DoS) conditions on an affected device by se… CWE-190Nov 28, 2023 | CVSS7.5v3.1 | EPSS0.881% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2023-4397MEDIUM | A buffer overflow vulnerability in the Zyxel ATP series firmware version 5.37, USG FLEX series firmware version 5.37, USG FLEX 50(W) series firmware version 5.37, and USG20(W)-VPN series firmware version 5.37, could allow an authenticated local attacker with administrator privileges to cause denial-of-service (DoS) conditions by executing the CLI command with crafted strings on an affected device. CWE-120Nov 28, 2023 | CVSS4.4v3.1 | EPSS0.233% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2023-37926MEDIUM | A buffer overflow vulnerability in the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLEX series firmware versions 4.50 through 5.37, USG FLEX 50(W) series firmware versions 4.16 through 5.37, USG20(W)-VPN series firmware versions 4.16 through 5.37, and VPN series firmware versions 4.30 through 5.37, could allow an authenticated local attacker to cause denial-of-service (DoS) conditions by executing the CLI command to dump system logs on an affected device. CWE-120Nov 28, 2023 | CVSS5.5v3.1 | EPSS0.221% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2023-37925MEDIUM | An improper privilege management vulnerability in the debug CLI command of the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLEX series firmware versions 4.50 through 5.37, USG FLEX 50(W) series firmware versions 4.16 through 5.37, USG20(W)-VPN series firmware versions 4.16 through 5.37, VPN series firmware versions 4.30 through 5.37, NWA50AX firmware version 6.29(ABYW.2), WAC500 firmware version 6.65(ABVS.1), WAX300H firmware version 6.60(ACHF.1), and WBE660S firmware version 6.65(… CWE-269Nov 28, 2023 | CVSS5.5v3.1 | EPSS0.218% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2023-35139MEDIUM | A cross-site scripting (XSS) vulnerability in the CGI program of the Zyxel ATP series firmware versions 5.10 through 5.37, USG FLEX series firmware versions 5.00 through 5.37, USG FLEX 50(W) series firmware versions 5.10 through 5.37, USG20(W)-VPN series firmware versions 5.10 through 5.37, and VPN series firmware versions 5.00 through 5.37, could allow an unauthenticated LAN-based attacker to store malicious scripts in a vulnerable device. A successful XSS attack could then result in the stored… CWE-79Nov 28, 2023 | CVSS5.2v3.1 | EPSS0.462% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2023-35136MEDIUM | An improper input validation vulnerability in the “Quagga” package of the Zyxel ATP series firmware versions 4.32 through 5.37, USG FLEX series firmware versions 4.50 through 5.37, USG FLEX 50(W) series firmware versions 4.16 through 5.37, USG20(W)-VPN series firmware versions 4.16 through 5.37, and VPN series firmware versions 4.30 through 5.37, could allow an authenticated local attacker to access configuration files on an affected device. CWE-20Nov 28, 2023 | CVSS5.5v3.1 | EPSS0.243% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |
CVE-2023-34141HIGH | A command injection vulnerability in the access point (AP) management feature of the Zyxel ATP series firmware versions 5.00 through 5.36 Patch 2, USG FLEX series firmware versions 5.00 through 5.36 Patch 2, USG FLEX 50(W) series firmware versions 5.00 through 5.36 Patch 2, USG20(W)-VPN series firmware versions 5.00 through 5.36 Patch 2, VPN series firmware versions 5.00 through 5.36 Patch 2, NXC2500 firmware versions 6.10(AAIG.0) through 6.10(AAIG.3), and NXC5500 firmware versions 6.10(AAOS.0)… CWE-78Jul 17, 2023 | CVSS8.0v3.1 | EPSS0.684% | PoCs0 | SignalsNot listed in CISA KEVNo known ransomware useNo Nuclei templates | STIX |