Reference stack outputs across accounts and Regions with AWS CloudFormation and CDK

Amazon Web Services has introduced a new CloudFormation intrinsic function called Fn::GetStackOutput that allows developers to reference stack outputs across different AWS accounts and regions directly within CloudFormation templates and CDK applications. The new capability addresses a longstanding challenge in multi-account AWS environments where teams previously needed to manually copy values between templates or coordinate parameter updates across teams to share infrastructure components like VPC IDs or database endpoints. The function works by allowing developers to specify a target stack name, output key, an IAM role ARN for cross-account access, and optionally a region. CloudFormation then assumes the specified role, retrieves the output value, and resolves it during template processing. For CDK applications, this functionality is now integrated automatically, replacing the previous approach that required custom resources and SSM parameters. The update also enables developers to create weak references between stacks, which simplifies the process of refactoring stack dependencies and eliminates deployment deadlocks that could occur when restructuring cross-stack dependencies in CDK applications.