cors – WordPress: console errors from web sites I have linked to

On this one page of my site,

I have hundreds of console errors that are coming from sites I have linked to in the posts displayed on the page. Security errors, iframe warning, font warnings etc.

I know what to do if these were errors on my site, but why am I getting errors about content that is not even on my site, but is on someone else’s that I have just hyperlinked to?

I have never seen anything like this before.