Release Asus RT-AX86 Series Firmware version 3.0.0.4.388_24386 9/1/2025

[iFrogMac]

ASUS RT-AX86 Series(RT-AX86U/RT-AX86S) Firmware version 3.0.0.4.388_24386

Version 3.0.0.4.388_24386

71.53 MB

2025/09/01

SHA-256 ：617E472529D16308D38A804445A555275898FA8A702713E20C257D5831C50C36

Important: After installing this firmware, we strongly recommend performing a factory-default reset to activate every new security adjustment.

Security Enhancements
- Password Policy Upgrade – Minimum 10 characters with at least 1 letter, 1 digit and 1 special symbol, and no consecutive identical characters; hardens defense against brute-force attacks.
- HTTPS on 8443 – Management interface now served over TLS by default.
- UPnP Disabled – Universal Plug and Play starts in the off state for reduced surface exposure.
- AiCloud Authentication Hardening (CWE-287) – Added layered verification.
- Authentication Logic Refactor – Removed redundant code paths for a lean sign-in flow.
- Memory Safety Guard (CWE-476) – Introduced null-reference protections across critical services.
- Enhanced IPsec Parameter Validation – The existing input checks have been hardened.
- Data Exposure Mitigation (CWE-200) – Reinforced controls on sensitive pathways.
- Detailed Audit Trails – Expanded logging within the authentication module.

System Improvements
- Connection Stability – Core algorithms refined for steadier links.
- Scheduling Accuracy – Timed tasks execute reliably under PPPoE, PPTP and L2TP WAN modes.
- Client List Maintenance – Resolved an issue that prevented offline devices from being removed from the client list.
Download link: https://www.asus.com/us/supportonly/rtax86u/helpdesk_bios/

 

[bennor]

Download link: https://www.asus.com/us/supportonly/rtax86u/helpdesk_bios/

Direct firmware download link: https://dlcdnets.asus.com/pub/ASUS/...X86U_RT_AX86S_300438824386.zip?model=RT-AX86U

 

[iFrogMac]

Direct firmware download link: https://dlcdnets.asus.com/pub/ASUS/...X86U_RT_AX86S_300438824386.zip?model=RT-AX86U

Thanks for providing the direct link. I wasn't sure if it was better to just provide the link to the Asus site, or direct to the firmware, or even both.

 

[kd4e]

For those who use the asuswrt-merlin firmware, is an update likely to be released - really soon, that includes all of this?

 

[bennor]

For those who use the asuswrt-merlin firmware, is an update likely to be released - really soon, that includes all of this?

Only person who knows is the developer, @RMerlin. And they can only do so if Asus provides the GPL's containing the updates to them.

 

[iFrogMac]

Even though I posted this thread, I haven't updated my router yet. I was curious, if I don't do the suggested factory reset that Asus recommends, how many of the new updates will not function as intended? I ask, because according to the list of changes, many of the settings I have made, are the new defaults on the new firmware. Also, if I were to backup my settings and restore on reconfigure, would it be the same as if I didn't factory reset at all?