We do not offer any ready-made data adapters to connect to 3rd party systems, or any other database solutions, but rather focus completely on rendering visualizations.
In terms of privacy/security/data processing, Highcharts, Highstock, Highmaps, and Highcharts Gantt are all client-side libraries.
They can be compared to frameworks like jQuery, React, and Angular on a practical level in terms of how they are used in 3rd party code.
There are no server-side components to either library, with the exception of when using the optional export module that turns charts into rasterized images.
You can, if you want, host the server-side component yourself if you require this module; and we also provide an offline version of it which does not require a server.
Highsoft does offer an (optional) CDN network for the client libraries (code.highcharts.com), but you can of course also download specific releases and target those in your application.
So to summarize, there are no data processing aspects in terms of Personal Data in our products, or storage of data of any kind.
Our libraries are simply included as a 100% client-side component into a target application.