ASUS
ASUS RT-AC66U: aging firmware and unpatched CVEs
The RT-AC66U is an aging AC1750 router that has accumulated unpatched CVEs on its most recent available firmware versions.
- Risk level
- High risk
- Category
- Routers and network
- Last reviewed
- 2026-05-23
- Confidence
- medium
Support status
Probable end of support: check ASUS changelog to confirm whether security patches are still being issued.
Typical symptoms
- Firmware on old version with no update offered
- Telnet or SSH admin exposed
- Unusual connection logs
Fixes to try
- Install the latest available ASUS firmware
- Disable Telnet, SSH and WAN admin access
- Enable firewall and filter exposed ports