Created Unassigned: HtmlEditorExtender bad "unsanitizing" image source tag [28031]

version 15.1.4 has problem with displaying more than ONE image SRC.
First image is correctly "unsanitized"/html decoded as

(spaces added for readability)
__& amp ;__
but second one
__& amp ; amp;__
third:
__& amp ; amp; amp;__
and so on...

bad output:
first: <img src="/getfile.ashx?ps=htmedit& amp ;rs=test.png">
second: <img src="/getfile.ashx?ps=htmedit& amp ; amp ;rs=test.png">test

how to reproduce:
- use htmleditorextender with ImageInsert enabled and EnableSanitization="true":
<Toolbar>
<ajaxToolkit:InsertImage />
</Toolbar>

- now in editor insert 2 or more images

- save it:
Dim s As String = HttpUtility.HtmlDecode(eTXTM1.Text)
s = s.Replace("& amp ; amp ;", "& amp ;") ' little workaround, doesnt helped
save it to DB or elsewhere

- reload into textbox in new page(full reload) on Page_Load:

If Not Page.IsPostBack Then
eTXTM1.Text = HttpUtility.HtmlDecode("saved text").ToString)
' value in eTXTM1.Text is so far so good. But at the end of page_load not.
end if

- boom and the __& amp ; i multiplicated