AWS CloudFormation introduces a new intrinsic function, Fn::GetStackOutput, enabling direct cross-account and cross-Region stack output references within CloudFormation templates and CDK applications. Previously, sharing infrastructure values like VPC IDs or database endpoints across account boundaries required manual copying or SSM parameter coordination. The new function accepts a target stack name, output key, IAM role ARN, and optional Region, then resolves the value automatically during template processing. In CDK, cross-account and cross-Region references now use this function automatically, removing the need for custom resources and SSM parameters, and eliminating deployment deadlocks when refactoring cross-stack dependencies. The feature is available in all AWS Regions where CloudFormation is supported.
