Exceptions.cs

using System;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;

public class HttpResponseExceptionFilter : IActionFilter, IOrderedFilter
{
    public int Order { get; } = int.MaxValue - 10;

    public void OnActionExecuting(ActionExecutingContext context)
    {
    }

    public void OnActionExecuted(ActionExecutedContext context)
    {
        if (context.Exception is not HttpResponseException exception) return;
        context.Result = new ObjectResult(exception.Message)
        {
            StatusCode = exception.StatusCode
        };
        context.ExceptionHandled = true;
    }
}

public class HttpResponseException : Exception
{
    public int StatusCode { get; }

    public HttpResponseException(string message, int statusCode = 400) : base(message)
    {
        StatusCode = statusCode;
    }
}