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Fencer Vulns
critical 9.8

CVE-2026-74232 json

Zbtlink MQWrt yunmgrd Cloud C2 Implant

published 2026-08-27 2 mo ago modified 2026-09-24 45 d ago also EUVD-2026-66999

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 57%
public exploits
0
none known

Summary

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.

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
total
Assessed
2 mo ago

Exploit prediction

0.81% chance of exploitation in the next 30 days, higher than 57% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • vulncheck.com http://vulncheck.com/blog/zbt-darklantern-speakingstone referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 9.3 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
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 4.0 9.3 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • Zbtlink L3_V2_8
  • Zbtlink WE826-T2
  • Zbtlink ZBT-7628
  • Zbtlink ZBT-ZBT7621
  • MoreQuick MQAC-7620
  • MoreQuick MQAC-7620A
  • MoreQuick MQAP-7620
  • MoreQuick MQAP-7620A
  • MoreQuick MQAP-7628
  • Unknown AP522
  • Unknown AP7628
  • Unknown APG721B
  • Unknown HC5661A
  • Unknown HK300
  • Unknown MAP-N10

Classification

Weakness
  • CWE-506 Embedded Malicious Code
  • CWE-300 Channel Accessible by Non-Endpoint

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.