Images uploaded with CKeditor disappear after cron run
Whatever text editor are you using either Basic HTML, Restricted HTML or Full HTML. 

In setting if Limit allowed HTML tags and correct faulty HTML is enabled under the Enable filters setting. Check under the Filter setting in the list of Allowed html tags, &lt;img&gt; tag has been enabled or not? If not listed in that list, the image will be strip off from the content as for that case it is restricted html element.

Update-1