Validation error on html5

I have a form which includes a 5 file upload from user, one of which is mandatory (required)

When I validate the HTML output I get this error:

Error: Element input is missing one or more of the following attributes: aria-expanded, aria-valuemax, aria-valuemin, aria-valuenow, role.

Can anyone suggest how to fix this problem?

Link to the page with validation error here

https://ww.wp.xz.cn/plugins/contact-form-7/