CVE-2026-74232: Zbtlink MQWrt yunmgrd Cloud C2 Implant

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% 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-300

Description

Zbtlink L3_V2_8 firmware 3.0.0.4.528, Zbtlink WE826-T2 firmware 19.1101, Zbtlink ZBT-7628 firmware 1.0.0.2.007, Zbtlink ZBT-ZBT7621 firmware 1.0.0.3.001, MoreQuick MQAC-7620, MQAC-7620A, MQAP-7620, MQAP-7620A, and MQAP-7628 firmware 1.0.0.2.000, AP522 firmware 1.0.0.2.014, AP7628 and HC5661A firmware 3.0.0.4.380, APG721B firmware 19.0809, HK300 firmware 1.0.0.2.032, and MAP-N10 firmware 1.0.0.2.044 ship a backdoor command-and-control implant (yunmgrd) reachable over an unauthenticated cleartext UDP channel to a hardcoded C2 server. A remote unauthenticated attacker on the network path can hijack the channel and execute arbitrary commands as root. The attacker can also modify DNS entries, exfiltrate PPPoE credentials, and open reverse SSH tunnels.

Affected products

MoreQuick MQAC-7620: 1.0.0.2.000
MoreQuick MQAC-7620A: 1.0.0.2.000
MoreQuick MQAP-7620: 1.0.0.2.000
MoreQuick MQAP-7620A: 1.0.0.2.000
MoreQuick MQAP-7628: 1.0.0.2.000
AP522: 1.0.0.2.014
AP7628: 3.0.0.4.380
APG721B: 19.0809
HC5661A: 3.0.0.4.380
HK300: 1.0.0.2.032
MAP-N10: 1.0.0.2.044
Zbtlink L3_V2_8: 3.0.0.4.528
Zbtlink WE826-T2: 19.1101
Zbtlink ZBT-7628: 1.0.0.2.007
Zbtlink ZBT-ZBT7621: 1.0.0.3.001

References

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