CVE-2026-66747
Backdoor in Zbtlink router firmware allows unauthenticated root remote access.
Is CVE-2026-66747 being exploited?
Not confirmed. CVE-2026-66747 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 0.66% probability of exploitation in the next 30 days.
How severe is CVE-2026-66747?
CVE-2026-66747 is rated Critical with a CVSS score of 9.3. 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-2026-66747?
Not known from our data. No patch reference has been recorded for CVE-2026-66747, 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-2026-66747 affect?
CVE-2026-66747 affects Zbtlink router firmware (all published builds), OpenWrt rctl package (librctl.so), Devices using vendor-provided Zbtlink/OpenWrt builds. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-66747?
Isolate affected devices, block outbound C2 (ports 7000/7001), replace firmware/device, apply vendor patch when released.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated remote code execution as root via cleartext TCP C2 callback; attacker can obtain an interactive root shell (rctlbash).
Immediate action required
- affected22.10.09
- affected21.04.07
- affected22.02.18_1
- affected23.08.12
- affected23.08.11
- affected21.03.22_1
- affected20.09.30
- affected22.08.10
- affected22.05.31
- affected22.05.31
- affected21.12.21
- affected21.08.06_1
- affected23.10.11
- affected23.03.16
- affected21.07.28
- affected22.05.30
- affected22.09.08
- affected21.03.23
- affected22.11.01
- affected7.6.7.2-25.0814_114432
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.