Cannot copy paste text with images from some specific websites

I'm not sure if this is a bug, or the expected behavior.

Steps to reproduce:
1. Open https://www.xwiki.org/xwiki/bin/view/Documentation/AdminGuide/Group%20Management inside any browser

2. Copy some text and one or multiple images at the same time using CTRL+C
3. Edit a XWiki page, using the in-place editor, or the WYSIWYG editor (realtime colaboration can be off, or on, the behavior is the same)

4. Paste the content using CTRL+V

Expected result:
The whole content is pasted inside the XWiki page (both text and image(s)) and the image can be viewed both in edit mode, and in view mode(after a save)

Actual result:
The text is pasted, but the image(s) is added as a link:

More details:

This happens when copy-pasting content from some websites, but not from others. I reproduced on:

• xwiki.org documentation page
• Gitlab (reproducible with content from the ticket description, but not with content from the comments)
• SharePoint

I reproduced both on XWiki 16.10.5 and 16.10.3
I reproduced using both Firefox (Version 137.0) and Chrome (135.0.7049)
There is no trace of this error in the server logs (with the standard/default logging options)

Selecting just the image and using CTRL+C and CTRL+V gives out the same CORS error

Right-clicking the image and selecting "Copy image" works for xwiki.org(the CORS error is still displayed in the browser console, but despite this, the image gets uploaded and displayed) and Gitlab, but does not for SharePoint(it still adds it as a link)