Steps to reproduce the issue

Use any existing form or create a form with a text field.
Pass input value mixed with character and integer multiple times like "test123test456" and submit.
Get input value of form field using input filtering method getInt() like below:
$integer = JFactory::getApplication->input->getInt( 'name_of_input_field' );

OR

(1) Open this file of your Joomla: components/com_search/controller.php
(2) Add below line in search() method as first line (Line: 46)
echo $this->input->getInt('searchword', null); die;
(3) Go to front-end of your joomla site and type "test123test456" in Joomla search input.
Above will show the filtered value submitted by search input.

Expected result

Variable should return "123456" as we have filtered integer values only

Actual result

But actually it returns "123" only. Means it returns first integer value occurrence only.

System information (as much as possible)

Joomla! 3.6.3-dev

Additional comments

The problem is in clean() method of libraries/joomla/filter/input.php library file.

I found that preg_match() returns only first occurrence on line no:167 for the input value.

Alternatively we can use pattern like below:
$pattern = '/[^-+0-9]/';

and preg_match() should replace with preg_replace() like below:
$matches = preg_replace($pattern, '', (string) $source);

Same issue I found with UINT case too.