A core dump consists of the recorded state of the working memory of a computer program at a specific time, generally when the program has terminated abnormally (crashed). Core dumps are often used to assist in diagnosing and debugging errors in computer programs.
A core dump file was found in this directory. The content of core dump files are highly sensitive as they contain the extact contents of the working memory including credentials, user data and so on.
It's recommended to configure the server not to create core dumps or to create the files in a directory that is not publicly accessible.