OS Command Injection in ZyXEL Communications Corp. products - CVE-2026-6952

Vulnerability identifier: #VU139078

CSH Severity: Low

CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-6952

CWE-ID: CWE-78

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote user to execute arbitrary shell commands on the target system.

The vulnerability exists due to improper input validation in the "LogServer" field of the syslog component. A remote administrator can pass specially crafted data to the application and execute arbitrary OS commands on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

EX7501-B0
EX3300-T1
EX3301-T0
EX3500-T0
EX3501-T0
EX3600-T0
EX5512-T0
PM5100-T1
EX5401-B1
EX5601-T0
EX5601-T1
PM5100-T0
DX3300-T0
EX7710-B0
GM4100-B0
VMG4005-B50A
VMG4005-B60A
PM3100-T0
AM7510-00
PE5301-01
AX7501-B1
PE3301-00
EX3300-T0
DX3300-T1
WX5600-T0
DX3301-T0
DX4510-B1
DX5401-B1
EE3301-00
WX3100-T0
EE5301-00
WE3300-00
EE6510-10
PM7500-00
EX2210-T0
PX5301-T0
PM7300-T0
VMG3625-T50B
VMG8623-T50B
EMG3525-T50B
EMG5523-T50B
DX4510-B0

Install updates from vendor's website.

EX7501-B0 - update to 5.18(ACHN.3.3)C0
EX3300-T1 - update to 5.50(ABVY.8.1)C0
EX3301-T0 - update to 5.50(ABVY.8.1)C0
PM7300-T0 - update to 5.42(ABYY.4.2)C0
EX3500-T0 - update to 5.44(ACHR.6)C0
EX3501-T0 - update to 5.44(ACHR.6)C0
EX3600-T0 - update to 5.70(ACIF.3.1)C0
EX5512-T0 - update to 5.70(ACEG.5.7)C0
PM5100-T1 - update to 5.42(ACBF.4.4)C0
EX5401-B1 - update to 5.17(ABYO.7.3)C0
EX5601-T0 - update to 5.70(ACDZ.6.1)C0
EX5601-T1 - update to 5.70(ACDZ.6.1)C0
PM5100-T0 - update to 5.42(ACBF.4.4)C0
DX3300-T0 - update to 5.50(ABVY.8.1)C0
EX7710-B0 - update to 5.18(ACAK.1.8)C0
GM4100-B0 - update to 5.18(ACCL.2.2)C0
VMG3625-T50B - update to 5.50(ABPM.9.9)C0
VMG4005-B50A - update to 5.17(ABQA.3.4)C0
VMG4005-B60A - update to 5.17(ABQA.3.4)C0
VMG8623-T50B - update to 5.50(ABPM.9.9)C0
PM3100-T0 - update to 5.42(ACBF.4.4)C0
AM7510-00 - update to 5.63(ACOR.0.3)C0
PE5301-01 - update to 5.63(ACOJ.3.2)C0
AX7501-B1 - update to 5.17(ABPC.8)C0
PE3301-00 - update to 5.63(ACMT.3.2)C0
EX3300-T0 - update to 5.50(ABVY.8.1)C0
DX3300-T1 - update to 5.50(ABVY.8.1)C0
WX5600-T0 - update to 5.70(ACEB.6.2)C0
DX3301-T0 - update to 5.50(ABVY.8.1)C0
DX4510-B0 - update to 5.17(ABYL.10.3)C0
DX4510-B1 - update to 5.17(ABYL.10.3)C0
DX5401-B1 - update to 5.17(ABYO.7.3)C0
EE3301-00 - update to 5.63(ACMU.3.2)C0
WX3100-T0 - update to 5.50(ABVL.5.1)C0
EE5301-00 - update to 5.63(ACLD.3.2)C0
WE3300-00 - update to 5.70(ACKA.2.1)C0
EE6510-10 - update to 5.19(ACJQ.4.3)C0
EMG3525-T50B - update to 5.50(ABPM.9.9)C0
PM7500-00 - update to 5.61(ACKK.1.5)C0
EX2210-T0 - update to 5.50(ACDI.2.6)C0
EMG5523-T50B - update to 5.50(ABPM.9.9)C0
PX5301-T0 - update to 5.44(ACKB.0.8)C0

• https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-post-authentication-command-injection-vulnerability-in-certain-dsl-ethernet-cpe-fiber-onts-and-wireless-extenders-07-21-2026

• OS Command Injection in Zyxel products