Embed HTML5 player for MP3 file

[Overgrow]

CSP maybe?

Mitigate XSS Attacks with Content Security Policy

What is Content Security Policy? Content Security Policy (CSP) is an added layer of security that helps to detect and mitigate certain types of attacks, including Cross Site Scripting (XSS) and data injection attacks. These attacks are used for everything from data theft to site defacement to distribution of malware. – Content Security Policy (CSP) - HTTP | MDN XSS is still one of the most common web vulnerability – if someone else can run scripts on your site, it is not your site anymore. …

Are you pasting it into post or …?