CVE-2025-13943

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-24 · updated 2026-06-17
Weakness: CWE-78

Description

A post-authentication command injection vulnerability in the log file download function of the Zyxel EX3301-T0 firmware versions through 5.50(ABVY.7)C0 could allow an authenticated attacker to execute operating system (OS) commands on an affected device.

Affected products

Zyxel Am7510-00 Firmware: before 5.63\(acoe.0.1\)c0 — fixed in 5.63\(acoe.0.1\)c0
Zyxel AX7501-B1 firmware: before 5.17\(abpc.7.1\)c0 — fixed in 5.17\(abpc.7.1\)c0
Zyxel Dm4200-B0 Firmware: before 5.17\(acbs.1.6\)c0 — fixed in 5.17\(acbs.1.6\)c0
Zyxel DX3300-T0 firmware: before 5.50\(abvy.7.1\)c0 — fixed in 5.50\(abvy.7.1\)c0
Zyxel DX3300-T1 firmware: before 5.50\(abvy.7.1\)c0 — fixed in 5.50\(abvy.7.1\)c0
Zyxel DX3301-T0 firmware: before 5.50\(abvy.7.1\)c0 — fixed in 5.50\(abvy.7.1\)c0
Zyxel Dx4510-B0 Firmware: before 5.17\(abyl.10.1\)c0 — fixed in 5.17\(abyl.10.1\)c0
Zyxel Dx4510-B1 Firmware: before 5.17\(abyl.10.1\)c0 — fixed in 5.17\(abyl.10.1\)c0
Zyxel Dx5401-B1 Firmware: before 5.17\(abyo.7.1\)c0 — fixed in 5.17\(abyo.7.1\)c0
Zyxel Ee3301-00 Firmware: before 5.63\(acmu.2.1\)c0 — fixed in 5.63\(acmu.2.1\)c0
Zyxel Ee5301-00 Firmware: before 5.63\(acld.2.1\)c0 — fixed in 5.63\(acld.2.1\)c0
Zyxel Ee6510-10 Firmware: before 5.19\(acjq.4.1\)c0 — fixed in 5.19\(acjq.4.1\)c0
Zyxel Emg3525-T50B Firmware: before 5.50\(abpm.9.7\)c0 — fixed in 5.50\(abpm.9.7\)c0
Zyxel Emg5523-T50B Firmware: before 5.50\(abpm.9.7\)c0 — fixed in 5.50\(abpm.9.7\)c0
Zyxel Emg6726-B10A Firmware: before 5.13\(abnp.8.2\)c1 — fixed in 5.13\(abnp.8.2\)c1
Zyxel Ex2210-T0 Firmware: before 5.50\(acdi.2.3\)c0 — fixed in 5.50\(acdi.2.3\)c0
Zyxel Ex3300-T0 Firmware: before 5.50\(abvy.7.1\)c0 — fixed in 5.50\(abvy.7.1\)c0
Zyxel Ex3300-T1 Firmware: before 5.50\(abvy.7.1\)c0 — fixed in 5.50\(abvy.7.1\)c0
Zyxel EX3301-T0 firmware: before 5.50\(abvy.7.1\)c0 — fixed in 5.50\(abvy.7.1\)c0
Zyxel Ex3500-T0 Firmware: before 5.44\(achr.5.1\)c0 — fixed in 5.44\(achr.5.1\)c0
Zyxel EX3501-T0 firmware: before 5.44\(achr.5.1\)c0 — fixed in 5.44\(achr.5.1\)c0
Zyxel EX3510-B0 firmware: before 5.17\(abup.15.2\)c0 — fixed in 5.17\(abup.15.2\)c0
Zyxel Ex3510-B1 Firmware: before 5.17\(abup.15.2\)c0 — fixed in 5.17\(abup.15.2\)c0
Zyxel Ex3600-T0 Firmware: before 5.70\(acif.2.1\)c0 — fixed in 5.70\(acif.2.1\)c0
Zyxel Ex5401-B1 Firmware: before 5.17\(abyo.7.1\)c0 — fixed in 5.17\(abyo.7.1\)c0
Zyxel Ex5510-B0 Firmware: before 5.17\(abqx.11.1\)c0 — fixed in 5.17\(abqx.11.1\)c0
Zyxel Ex5512-T0 Firmware: before 5.70\(aceg.5.3\)c0 — fixed in 5.70\(aceg.5.3\)c0
Zyxel Ex5601-T0 Firmware: before 5.70\(acdz.5.1\)c0 — fixed in 5.70\(acdz.5.1\)c0
Zyxel EX5601-T1 firmware: before 5.70\(acdz.5.1\)c0 — fixed in 5.70\(acdz.5.1\)c0
Zyxel Ex7501-B0 Firmware: before 5.18\(achn.3.1\)c0 — fixed in 5.18\(achn.3.1\)c0

How to fix

Upgrade to a fixed version: Zyxel Am7510-00 Firmware 5.63\(acoe.0.1\)c0; Zyxel AX7501-B1 firmware 5.17\(abpc.7.1\)c0; Zyxel Dm4200-B0 Firmware 5.17\(acbs.1.6\)c0; Zyxel DX3300-T0 firmware 5.50\(abvy.7.1\)c0; Zyxel DX3300-T1 firmware 5.50\(abvy.7.1\)c0; Zyxel DX3301-T0 firmware 5.50\(abvy.7.1\)c0; Zyxel Dx4510-B0 Firmware 5.17\(abyl.10.1\)c0; Zyxel Dx4510-B1 Firmware 5.17\(abyl.10.1\)c0; Zyxel Dx5401-B1 Firmware 5.17\(abyo.7.1\)c0; Zyxel Ee3301-00 Firmware 5.63\(acmu.2.1\)c0; Zyxel Ee5301-00 Firmware 5.63\(acld.2.1\)c0; Zyxel Ee6510-10 Firmware 5.19\(acjq.4.1\)c0. Check the vendor advisory for mitigations.

References

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-null-pointer-dereference-and-command-injection-vulnerabilities-in-certain-4g-lte-5g-nr-cpe-dsl-ethernet-cpe-fiber-onts-security-routers-and-wireless-extenders-02-24-2026

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