Steps to reproduce:
- create a new page
- edit the content in the standard wywisyg editor, before saving the page (in the editor displayed after hitting "Create" in the create form)
- upload an image, using the image menu of the wysiwyg editor or by pasting the image from the clipboard (in supported browsers)
- the page is saved with the typed content and the image
Doesn't reproduce on a 12.6.2 so it's a regression.