CVE-2026-74233

Zbtlink MQWrt infosrvd Command Injection

State: Published
Severity: 9.3 Critical
Published: Aug 27, 2026
Updated: Aug 27, 2026
Reserved: Aug 14, 2026

Description

Zbtlink WE1326, WE357, WE5926, WE5926-WD, WE826-Q, WE826-T2, WE826-WD, WG108, and WG3526 firmware 19.1101, Zbtlink WE2426-C firmware 19.1112, Zbtlink WE5926-EC_QP firmware 20.0516, Zbtlink WF3526-P firmware 19.051, CTN720-W1, LF-1541, and MT7620N firmware 19.1101, and WRC1 firmware 20.0622 contain an unauthenticated command injection in the infosrvd service (UDP/9992). A remote unauthenticated attacker can send a crafted UDP packet to execute arbitrary commands as root. The service's authentication uses a hardcoded salt and an all-zero wildcard MAC bypass, rendering it ineffective.

Scores

CVSS	Score	Vector	Source
4.0	9.3 Critical	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N	VulnCheck
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	VulnCheck

Weaknesses

CWE-321 Use of Hard-coded Cryptographic Key
CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Affected Products

Product	Versions
WE1326Zbtlink	19.1101Affected
WE2426-CZbtlink	19.1112Affected
WE357Zbtlink	19.1101Affected
WE5926Zbtlink	19.1101Affected
WE5926-EC_QPZbtlink	20.0516Affected
WE5926-WDZbtlink	19.1101Affected
WE826-QZbtlink	19.1101Affected
WE826-T2Zbtlink	19.1101Affected
WE826-WDZbtlink	19.1101Affected
WF3526-PZbtlink	19.051Affected
WG108Zbtlink	19.1101Affected
WG3526Zbtlink	19.1101Affected
CTN720-W1Unknown	19.1101Affected
LF-1541Unknown	19.1101Affected
MT7620NUnknown	19.1101Affected
WRC1Unknown	20.0622Affected

References

VulnCheck Blogtechnical-descriptionexploit
https://www.vulncheck.com/advisories/zbtlink-mqwrt-infosrvd-command-injectionthird-party-advisory

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