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IoT

CVE-2026-51754

9.8
Critical
EPSS 0.43%Sep 4, 2026

Unauthenticated MQTT flaw allows overwriting slave IP list on TOTOLINK T6 router.

common questions

Is CVE-2026-51754 being exploited?

Not confirmed. CVE-2026-51754 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.43% probability of exploitation in the next 30 days.

How severe is CVE-2026-51754?

CVE-2026-51754 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2026-51754?

Not known from our data. No patch reference has been recorded for CVE-2026-51754, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.

What does CVE-2026-51754 affect?

CVE-2026-51754 affects TOTOLINK T6 (firmware 4.1.5cu.748_B20211015), cs_broker MQTT component. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

What should I do about CVE-2026-51754?

Isolate affected devices, block MQTT ingress, monitor logs, apply vendor firmware when available.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

executive summary
technical analysis
affected
TOTOLINK T6 (firmware 4.1.5cu.748_B20211015)cs_broker MQTT component
impact

Unauthenticated remote overwrite of slave IP list via MQTT, enabling network disruption, management hijack, or persistent access.

action required

Immediate action required

how to fix
Remediation steps are tailored for users whose stack is affected. Add this technology to your stack to see the fix checklist.
references
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