[FIRMWARE] for UAP/USW has been released | Stable

by Ubiquiti Employee on ‎02-04-2019 10:07 AM - last edited yesterday (56,083 Views)

We've prepared firmware Please see below for the changelog and links to the firmware binaries. Note that all 1st gen UAPs (UAP, UAP-LR, UAP-OD, UAP-OD5, UAP-OD+, UAP-IW, UAP-Pro, UAP v2, UAP-LR v2) were skipped for this stable release.


Firmware changes since 4.0.15

  • [UAPG2] Improve latency in high traffic installations.
  • [HD/SHD/XG/BaseStationXG] Improve stability.
  • [HD/SHD/XG/BaseStationXG] Optimize multicast traffic.
  • [nanoHD/IW-HD] Fix DTIM provisioning issue.
  • [nanoHD/IW-HD] Fix a bug in TX power provisioning.
  • [nanoHD/IW-HD] Fix WiFi Experience feature (reported HERE).
  • [nanoHD/IW-HD] Fix bandsteering disconnection issue.
  • [nanoHD/IW-HD] Fix wireless uplink bandwidth mismatch issue.
  • [nanoHD/IW-HD] Fix displayed RX rate issue (reported HERE).
  • [nanoHD/IW-HD] Fix available channel list for China.
  • [nanoHD/IW-HD] Fix fast-apply issue with changing channel width.
  • [nanoHD/IW-HD] Fix data forwarding issue when client STA roams from wired AP to a wireless uplinked AP. 
  • [IW-HD] Fix wired 802.1X Auto mode.
  • [UAP] Tweak Wi-Fi Experience scoring.
  • [UAP] Improve wireless uplink loop detection feature. 
  • [UAP] Fix a bug that may cause MAC ACL and bandsteering to conflict in certain configurations.
  • [UAP] Fix uplink detection function.
  • [UAP] Fix ifindex reporting via SNMP.
  • [UAP] Fix the VLAN provisioning bug introduced in 4.0.18.
  • [UAP] Properly isolate dynamic VLANs.**
  • [UAP] Security improvement for guest authentication.*
  • [XG6POE] Improve PD auto detect. 
  • [XG6POE] Fix PoE issue which may occur on device reboot (reported HERE). 
  • [USW] Fix various bugs causing WiFi clients to show as wired once disconnected from WiFi network (reported HERE).
  • [HW] Fix CVE-2019-5747.
  • [HW] Miscellaneous bug fixes and improvements.

*Controller support pending.

**Currently excluding nanoHD/IW-HD (WIP). All other models that support this feature are fixed.



  • You may start to see EVT_AP_RestartProc events in the controller log. If you see these, please report if there is anything specifically in your setup that triggers the events. The processes restarting is not new, but the reporting of the restarting is, and we are using these reports to clean up these issues.
  • Any US-XG-6POE upgrading from 4.0.2 or earlier will take a long time to upgrade. Don't be surprised if your switch is unavailable for 5-10+ minutes as 4.0.3+ also updates the PoE firmware to improve PD compatibility.
  • 1st gen UAPs may require extra steps when upgrading from firmware 4.0.3. You can try disabling all WLAN groups, and then running the upgrade. Devices that are seemingly "stuck" on 4.0.3 may require TFTP recovery to upgrade from that firmware.

  • All supported 1st gen APs need to be on a minimum of 4.0.10 prior to upgrading to this firmware. Controller 5.10.3+ will force an upgrade to 4.0.10 prior to upgrading to this release (only if your device isn't running 4.0.10 already). 



  • If your 1st gen UAPs are running 4.0.21, and they're working for your needs, then you can leave those devices on 4.0.21. There is no need to revert. We just want to fix a few bugs since the switch to LEDE framework.




*This firmware is meant to be a one file solution that works with all models of UniFi switch. You can use it when upgrading from 3.9.40+ only. It will not work when upgrading from earlier releases.


Any and all feedback is welcome, including lettings us know about successful device upgrades. When reporting an issue, please ensure that you include the following information:

  1. Controller version.
  2. Firmware version (previous and current). 
  3. Device model(s). 

Links are all HTTPS. This assumes your device(s) are currently running at least 3.7.51, and that the device's date is properly set (i.e. it can reach a NTP server). If you encounter issues with the upgrade, or your device isn't on a minimum supported firmware, then you can change the link to HTTP before performing the upgrade.