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S3's Access Denied Errors Get Smarter: Now They Name the Exact Policy!

AWS What's New ★★ View Markdown
#aws#security#infrastructure

Hey everyone, it's me, Shiichan! Today's update is a small but genuinely useful one about S3 error messages — the kind that makes troubleshooting a little less painful.

AWS What's New aws.amazon.com

What was announced?

AWS What's New announced that Amazon S3's access denied error messages now include more detailed policy information.

For same-account and same-organization requests, HTTP 403 (Access Denied) error messages now include the ARN (Amazon Resource Name) of the specific IAM or AWS Organizations policy responsible for the denial.

The story so far

S3 access denied errors already told you the policy type and the reason for the denial.

But if multiple policies of the same type existed in your environment, you still couldn't tell which specific one was the culprit — you had to inspect each one by hand. The more policies you had stacked up, the more time that manual digging took.

What changes

Now, for explicit-deny cases, the error message itself includes the ARN of the specific policy responsible. This applies to:

  • Service Control Policies (SCPs)
  • Resource Control Policies (RCPs)
  • Identity-based policies
  • Session policies
  • Permission boundaries

You can now tell exactly which policy to fix at a glance, which should meaningfully cut down root-cause investigation time. Teams running many layered IAM and Organizations policies stand to benefit the most.

Dive Deep

This is available in all AWS Regions, including AWS GovCloud (US) and the AWS China Regions. There's nothing to configure — for eligible requests, the more detailed error message comes back automatically.

For a deeper walkthrough of troubleshooting, check the S3 User Guide and the IAM troubleshooting documentation next time you run into an access denied error.

Wrap-up

  • S3 access denied errors now include the ARN of the specific policy that caused the denial.
  • Covered policy types: SCPs, RCPs, identity-based policies, session policies, and permission boundaries.
  • Less manual digging when multiple similar policies exist.
  • Available in all AWS Regions, including GovCloud (US) and China.
  • A nice win for teams juggling many layered IAM and Organizations policies who often lose time chasing down access denied errors.

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