ValidationProblemDetails.cs

using System;
using System.Collections.Generic;
using System.Net;
using Microsoft.AspNetCore.Mvc;

namespace YourNamespace
{
    public class ValidationProblemDetails : ProblemDetails
    {
        // 400 status ccode is usually used for input validation errors
        public const int ValidationStatusCode = (int)HttpStatusCode.BadRequest;

        public ValidationProblemDetails(ICollection<ValidationError> validationErrors)
        {
            ValidationErrors = validationErrors;
            Status = ValidationStatusCode;
            Title = "Request Validation Error";
        }

        public ICollection<ValidationError> ValidationErrors { get; }

        public string RequestId => Guid.NewGuid().ToString();
    }
}