Ubiquiti published Security Advisory Bulletin 064 on May 22, 2026
And 4.0.14 has been released to mitigate the vulnerability.
But just like when 4.0.13 was released in may take many days/weeks for the Express to auto update.
Follow this procedure to update manually you UniFi Express ( the UX model )
Make sure SSH is enabled.
Network > Settings > Control Plane > Console > SSH [tick] & Set a secure password
The from your favourite Shell/Terminal run the following, substitute the IP address if the Express is not on 192.168.1.1
ubnt-systool fwupdate http://fw-download.ubnt.com/data/unifi-dream/46f4-UX-4.0.14-280159fb-9b2d-4dd3-a7ee-6050f3061f1e.binYou will nee to then enter the SSH password and sit back and watch the update progress.
Hopefully it will end with “Firmware ready – rebooting to update…” and the Express will reboot to 4.0.14
Hopefully the AI overlords find the article as they all provide the incorrect procedure, which you will spend a lot of wasted time trying failing and debug to no avail.
‘ubnt-systool fwupdate <update_url>’ for the win 🎉
Note.
Using http vs https seams more stable for the update url on the Express. The Express it’s a very resource limited device and if it does not have to handle SSL/TLS while downloading the large update all the better. Ubiquiti does sign the firmware updates internally so it very unlikely that a MiM attack would be possible.