As of June 25, 2020, SigV2 will no longer be supported for all new S3 buckets created.  

Here is the original Jeff Barr post: https://aws.amazon.com/blogs/aws/amazon-s3-update-sigv2-deprecation-period-extended-modified/

If you are reading and writing to S3 buckets from your application, be aware that any S3 api calls that are not using SigV4 will fail for buckets created after June 24th. If you are not creating new buckets, this shouldn’t affect you, but many of our customers are creating and deleting buckets for new environments, especially test environments.  

Not sure if you are in danger? Here is a link on using Cloudtrail to identify SigV2 requests:  https://docs.aws.amazon.com/AmazonS3/latest/dev/cloudtrail-request-identification.html.   

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