In WordPress before 4.7.5, a cross-site scripting (XSS) vulnerability exists when attempting to upload very large files, because the error message does not properly restrict presentation of the filename.
https://wpvulndb.com/vulnerabilities/8819
https://wordpress.org/news/2017/05/wordpress-4-7-5/
https://github.com/WordPress/WordPress/commit/8c7ea71edbbffca5d9766b7bea7c7f3722ffafa6
https://codex.wordpress.org/Version_4.7.5
http://www.securitytracker.com/id/1038520