Missing bucket ownership verification in Amazon SageMaker Python SDK default_bucket()

Bulletin ID: 2026-142-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 10/21/2026 12:30 PM PDT Description: The Amazon SageMaker Python SDK is an open-source library for training and deploying machine learning models on Amazon SageMaker. We identified CVE-2026-112408, an issue in the default_bucket() function. The SDK uses a predictably named Amazon S3 bucket and does not check that the caller's AWS account owns it. A remote actor who creates that bucket first could achieve code execution in a remote SageMaker execution environment and obtain IAM credentials. Impacted versions: - V2: = 3.0.0 and < 3.10.0 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin. Read this article