CVE-2026-74233: Zbtlink MQWrt infosrvd Command Injection

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-27 · updated 2026-09-24
Weakness: CWE-78

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.

Affected products

CTN720-W1: 19.1101
LF-1541: 19.1101
MT7620N: 19.1101
WRC1: 20.0622
Zbtlink WE1326: 19.1101
Zbtlink WE2426-C: 19.1112
Zbtlink WE357: 19.1101
Zbtlink WE5926: 19.1101
Zbtlink WE5926-EC_QP: 20.0516
Zbtlink WE5926-WD: 19.1101
Zbtlink WE826-Q: 19.1101
Zbtlink WE826-T2: 19.1101
Zbtlink WE826-WD: 19.1101
Zbtlink WF3526-P: 19.051
Zbtlink WG108: 19.1101
Zbtlink WG3526: 19.1101

References

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