i copied this in the cms (ctrl + c)

<h3>New Business Manager</h3>
<p>An ideal candidate would be responsible for launching products into new markets and attaining new customers.</p>
<p>Apply now..</p>

and i pasted into the same page, directly below (ctrl + v) and the html it copied was..

<h3 style="font-size: 1.17em;">New Business Manager</h3>
<p>An ideal candidate would be responsible for launching products into new markets and attaining new customers.</p>
<p><span style="vertical-align: baseline; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: transparent; outline-width: 0px; outline-style: initial; outline-color: initial; padding: 0px; margin: 0px;">Apply now..</span></p>

why all the extra html l tags?

note - all html code shown here, but when copy and paste it was with just the "styled text" showing in the Content area, silverstripe version 2.4.5

hi,

I think you have to try out the paste as plain text for this. This is not a tinyMCE issue as far as I know.
if you are copying from MS Word this will be more messy