You can disable paste in your input as follows:

html:

<input type="text" value="" id="myInput">

javascript:

window.onload = () => {

 const myInput = document.getElementById('myInput');

 myInput.onpaste = e => e.preventDefault();

}

Talking about security, I wouldn't say that this makes any impact. You would usually use client side and well as server-side validation of data submitted by the user.