CVE-2026-51699
Unauthenticated DMZ config vuln in TOTOLINK T6 allows exposing internal hosts.
Is CVE-2026-51699 being exploited?
Not confirmed. CVE-2026-51699 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-2026-51699?
CVE-2026-51699 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-2026-51699?
Not known from our data. No patch reference has been recorded for CVE-2026-51699, 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-2026-51699 affect?
CVE-2026-51699 affects TOTOLINK T6 (firmware 4.1.5cu.748_B20211015), /cgi-bin/cstecgi.cgi - setDmzCfg. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-51699?
Block WAN access to router CGI, isolate devices, apply vendor firmware update when available.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated remote POST to /cgi-bin/cstecgi.cgi can set DMZ to expose internal hosts to the internet, enabling remote access, lateral movement, and data theft.
Immediate action required