Hi everyone,
Since upgrading to Home Assistant Core 2026.9.1, my frontend becomes inaccessible from the local network after restarting Home Assistant Core.
My setup:
- Raspberry Pi 4
- Home Assistant OS 18.2
- Home Assistant Core 2026.9.1
- Supervisor 2026.09.0
- aarch64
- HA IP address:
192.168.1.114
After a normal restart:
$ ss -lntp | grep 8123
LISTEN 0 128 127.0.0.1:8123 0.0.0.0:*
The frontend is therefore only available from localhost and cannot be accessed at http://192.168.1.114:8123.
The Core logs show:
Error handling when_setup callback for frontend
File ".../components/http/server.py", line 548, in start
await self._server.start_serving()
OSError: [Errno 98] Address in use
What is strange is that the HTTP configuration explicitly contains:
"server_port": 8123,
"server_host": [
"0.0.0.0",
"127.0.0.1",
"::1"
]
I also verified that no other process is using port 8123 before Home Assistant starts:
ha core stop
ss -lntp | grep 8123
→ no result.
Then:
ha core start
ss -lntp | grep 8123
→ 127.0.0.1:8123 appears.
I also temporarily removed the entire /config/custom_components directory. The problem remained unchanged.
At one point, restarting Home Assistant in Safe Mode resulted in:
0.0.0.0:8123
and the frontend was then accessible from the LAN. However, subsequent Safe Mode restarts reproduced the localhost-only behaviour, so Safe Mode is not currently a reliable workaround.
The network itself is working correctly. When Home Assistant does listen on 0.0.0.0:8123, the frontend is immediately accessible from the LAN.
Has anyone else experienced this behaviour with Core 2026.9.x?
I am also opening a GitHub issue with the detailed logs and troubleshooting results (Core 2026.9.1 binds HTTP server to 127.0.0.1 and fails with EADDRINUSE on port 8123 · Issue #181870 · home-assistant/core · GitHub).
Thanks!