这是一个不完美的解决方案，它迫使Wordpress检测TTF文件的方式使用文件扩展名，然后挂钩upload_mimes 对于我们指定的MIME类型。部分答案摘自https://diviengine.com/how-to-fix-sorry-this-file-type-is-not-permitted-for-security-reasons/

首先介绍Wordpress检测/报告TTF文件类型的方式：

function divi_engine_font_correct_filetypes( $data, $file, $filename, $mimes, $real_mime ) {

if ( ! empty( $data[\'ext\'] ) && ! empty( $data[\'type\'] ) ) {
return $data;
}

$wp_file_type = wp_check_filetype( $filename, $mimes );

// Check for the file type you want to enable, e.g. \'svg\'.
if ( \'ttf\' === $wp_file_type[\'ext\'] ) {
$data[\'ext\'] = \'ttf\';
$data[\'type\'] = \'font/ttf\';
}

if ( \'otf\' === $wp_file_type[\'ext\'] ) {
$data[\'ext\'] = \'otf\';
$data[\'type\'] = \'font/otf\';
}

return $data;
}
add_filter( \'wp_check_filetype_and_ext\', \'divi_engine_font_correct_filetypes\', 10, 5 );

function allow_custom_mime_types( $mimes ) {
 
    // New allowed mime types.
    $mimes[\'ttf\'] = \'font/ttf\';     

    return $mimes;
}

add_filter( \'upload_mimes\', \'allow_custom_mime_types\' );