I have found jQuery versions hidden in the following places while updating our client's sites.
- Codebase (phtml/xml files)
- Backend Config HEAD/Footer html areas
- CMS Blocks
- Modules / JS Libraries loading their own version of jQuery
First thing would be to check if its within the backend header/footer script inputs in system config
Then using dev tools search function within the drawer, search for strings related to your jQuery instance (usually version number works), eg
You should be able to identify now the filename/path that the jQuery is loading from and whether it's embedded within a JS library or packaged with a module.
If you can't manually find where it's being injection from with the filename and path. You can try searching all the files in your Magento install with grep, replacing the jQuery string with the js file that jQuery is contained in or even just the jQuery version number could work
- If server SSH into it
grep -rl "jQuery.1.12.0.min.js" /path/to/magento/install
If you still can't find it within the files, you could try to check CMS static blocks/pages with SQL
SELECT * FROM cms_block WHERE content LIKE '%jQuery.1.12.0.min.js%';
SELECT * FROM cms_page WHERE content LIKE '%jQuery.1.12.0.min.js%';