Hiya,

according to https://snyk.io/test/npm/jquery/1.11.3 , there are some medium vulnerabilities in jQuery 1.11.3.
Looking at themes/default/js/jquery.min.js , Piwigo uses
/*! jQuery v1.11.3 | (c) 2005, 2015 jQuery Foundation, Inc. | jquery.org/license */

I can't judge whether this is an issue, apparently jquery.cookie.js is also not maintained anymore:

/*!
* jQuery Cookie Plugin v1.4.1
* https://github.com/carhartl/jquery-cookie
*
* Copyright 2013 Klaus Hartl
* Released under the MIT license
*/

- should these be upgraded to more recent versions ? If so, what's the best way to update, is jQuery Migrate 1.4.1 a recommended option ?