
CVE-2026-112408, AWS bulletin 2026-142, coordinated disclosure with Dan Gansel (Upwind). Upgrade to the latest sagemaker (V3 3.22.1+ also closes the fine-tuning paths; V2 2.257.3+), or pass a default_bucket you own. No exploitation reported. https://github.com/aws/sagemaker-python-sdk/security/advisories/GHSA-5rx8-8fr2-f855
