CVE-2026-51765Network attack vector

Unauthenticated mesh record manipulation via MQTT

Published Sep 1, 2026 · Updated Sep 2, 2026

Incorrect access control in TOTOLINK T6 4.1.5cu.748_B20211015 allows remote attackers to alter mesh neighbor records via crafted MQTT messages. The recvIndirectMeshInfo function in cs_broker accepts attacker-supplied macAddr and ipAddr fields and inserts or replaces the corresponding mesh-neighbor entry without authentication. Network reachability to the MQTT service is sufficient; successful exploitation corrupts the router's mesh topology state rather than directly disclosing stored data or executing code.

CVSS severity9.8
Critical
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect access control in TOTOLINK T6 4.1.5cu.748_B20211015 allows remote attackers to alter mesh neighbor records via crafted MQTT messages. The recvIndirectMeshInfo function in cs_broker accepts attacker-supplied macAddr and ipAddr fields and inserts or replaces the corresponding mesh-neighbor entry without authentication. Network reachability to the MQTT service is sufficient; successful exploitation corrupts the router's mesh topology state rather than directly disclosing stored data or executing code.

The record

CVE
CVE-2026-51765
Published
Sep 1, 2026
Updated
Sep 2, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-284, T1565.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 2, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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