CVE-2026-51751
Unauthenticated MQTT allows removal of mesh devices and remote reboot on TOTOLINK T6.
Is CVE-2026-51751 being exploited?
Not confirmed. CVE-2026-51751 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 0.44% probability of exploitation in the next 30 days.
How severe is CVE-2026-51751?
CVE-2026-51751 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-2026-51751?
Not known from our data. No patch reference has been recorded for CVE-2026-51751, 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-2026-51751 affect?
CVE-2026-51751 affects TOTOLINK T6 (firmware 4.1.5cu.748_B20211015), cs_broker component, mesh management (delSlaveDevice). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-51751?
Block MQTT access (1883/8883), isolate affected devices, apply vendor firmware when released.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated attacker can send crafted MQTT to cs_broker to remove mesh slave entries and reboot the router, causing network disruption/DoS.
Immediate action required