core Caldav is broken

The problem

For some weeks, I very often get the error Connection reset by peer when using the Caldav integration. Other apps (and a manual test) have no problem accessing the server using these credentials.

I also noticed that the caldav library is outdated, maybe that would be a good first step?

What version of Home Assistant Core has the issue?

core-2025.9.4

What was the last working version of Home Assistant Core?

No response

What type of installation are you running?

Home Assistant Container

Integration causing the issue

CalDav

Link to integration documentation on our website

https://www.home-assistant.io/integrations/caldav/

Diagnostics information

Nothing of interest was included

Example YAML snippet

Anything in the logs that might be useful for us?

Additional information

On first glance, it looks a lot like #143075

Sep 28 '25 14:09 fdw

caldav documentation caldav source

Sep 28 '25 14:09 home-assistant[bot]

Is "my" problem linked to this issue? ( https://github.com/home-assistant/core/issues/153046#issue-3457609906 )

Oct 01 '25 07:10 HaraldGithub

My App Passwort within apple was gone, so I created a new one and this solved my problem

Oct 04 '25 08:10 TylonHH

It works intermittently, so it can fetch events every now and then, but at least at often, it fails. This should not be related to a password then 😉

Oct 04 '25 08:10 fdw

@fdw I experienced the same behaviour for many weeks (using mailbox.org), but as of 2025.12 it seems to be fixed, i.e. I've never seen the unavailable status anymore since this upgrade.

How about you? I didn't see any version bump for the CalDav integration in the latest release notes, but I might have missed it.

Dec 09 '25 21:12 smnmsr