Issue 11662: Fix vulnerability in urllib/urllib2.
(This version is a cleaned-up backport of a fix by Senthil Kumaran.)
diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
index fe61030..b4a7f28 100644
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -783,6 +783,10 @@
    is the case, :exc:`HTTPError` is raised.  See :rfc:`2616` for details of the
    precise meanings of the various redirection codes.
 
+   An :class:`HTTPError` exception raised as a security consideration if the
+   HTTPRedirectHandler is presented with a redirected url which is not an HTTP,
+   HTTPS or FTP url.
+
 
 .. method:: HTTPRedirectHandler.redirect_request(req, fp, code, msg, hdrs, newurl)