Access through plex.tv doesn't work in chrome, when plex media server is on the same nwtwork

[pigster6]

Hi

when trying to access plex media server from home network through plex.tv, it fails.

the reason is new chrome security feature to disallow local network access from remote site when Access-Control-Allow-Private-Network is missing

I see following error in console:

Access to XMLHttpRequest at 'https://192-168-55-100....' from origin 'https://app.plex.tv' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Private-Network' header was present in the preflight response for this private network request targeting the private address space.

Plex will also try to go through public IP first, but that fails when you are on the same local network as plex media server.

Access from outside of the home network works just fine.

Firefox works fine from both local network and internet.

See Private Network Access for details

Plex media server version: 1.29.0.6244

[OttoKerner]

I can’t recreate it here on my Chrome browser.
Is this something you need to enable first?

[pigster6]

I don’t think you need to enable anything

There is a chrome flag chrome://flags/#block-insecure-private-network-requests but by default it is ON on latest versions of Chrome

Also google released a blog post about this “feature” Private Network Access update: Introducing a deprecation trial - Chrome Developers

My version of chrome is 106.0.5249.103 (Official Build) (64-bit)

[OttoKerner]

Same version as here. But my Chrome is not a new install but was upgraded.

The flag is shown as “Default”.

[OttoKerner]

Is it possible that you have a DNS rebinding issue on your local network?

[pigster6]

I have found it

it is also enabled if this flag chrome://flags/#enable-experimental-web-platform-features is enabled

though you will have to fix it anyway, as according to the mentioned blog post, this will be the default from February 2023