Connector/C++ causes a segfault when the application uses the std::regex constructor. This was previously noted in another bug reported by Lawrin Novitsky. The previous bug was not researched/fixed but provided a work-around to use GCC revision >4.9 imposed by cmake.
I downloaded and compiled the MariaDB c+/connector on my server, and that fixed the problem. The MariaDB binary provided, as you indicated, uses c+ regex in its ParseUrl.cpp. Since it was compiled with an older version of GCC, the lib had a conflict with the current GCC implementation. I would suggest that you think about refactoring your code to not use the regex for this type of parsing, as it is slow to compile and run, and also produces a much larger executable that is generally required for simple parsing.
Thanks for your help