HTTP 400 status code (Bad Request) - Amazon CloudFront
Amazon S3 origin returns a 400 errorApplication Load Balancer origin returns a 400 error

HTTP 400 status code (Bad Request)

CloudFront returns a 400 bad request when the client sends some invalid data in the request such as missing or incorrect content in the payload or parameters. This could also represent a generic client error.

Amazon S3 origin returns a 400 error

If you're using an Amazon S3 origin with your CloudFront distribution, your distribution might send error responses with HTTP status code 400 Bad Request, and a message similar to the following:

The authorization header is malformed; the region '<AWS Region>' is wrong; expecting '<AWS Region>'

For example:

The authorization header is malformed; the region 'us-east-1' is wrong; expecting 'us-west-2'

This problem can occur in the following scenario:

  1. Your CloudFront distribution's origin is an Amazon S3 bucket.

  2. You moved the S3 bucket from one AWS Region to another. That is, you deleted the S3 bucket, then later you created a new bucket with the same bucket name, but in a different AWS Region than where the original S3 bucket was located.

To fix this error, update your CloudFront distribution so that it finds the S3 bucket in the bucket's current AWS Region.

To update your CloudFront distribution

  1. Sign in to the AWS Management Console and open the CloudFront console at https://console.aws.amazon.com/cloudfront/v4/home.

  2. Choose the distribution that produces this error.

  3. Choose Origins and Origin Groups.

  4. Find the origin for the S3 bucket that you moved. Select the check box next to this origin, then choose Edit.

  5. Choose Yes, Edit. You do not need to change any settings before choosing Yes, Edit.

When you complete these steps, CloudFront redeploys your distribution. While the distribution is deploying, you see the Deploying status under the Last modified column. Some time after the deployment is complete, you should stop receiving the AuthorizationHeaderMalformed error responses.

Application Load Balancer origin returns a 400 error

If you're using an Application Load Balancer origin with your CloudFront distribution, possible causes of a 400 error include the following:

  • The client sent a malformed request that does not meet the HTTP specification.

  • The request header exceeds 16 KB per request line, 16 KB per single header, or 64 KB for the entire request header.

  • The client closed the connection before sending the full request body.