Vulnerability · Published Oct 21, 2026 · Assigned by AMZN

CVE-2026-112408Missing bucket ownership verification in Amazon SageMaker Python SDK default_bucket()

High 8.1

In plain English

A high-severity security flaw in Amazon SageMaker Python SDK from AWS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 55% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.7%top 45.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Missing verification of source of a communication channel in the default_bucket() function in Amazon SageMaker Python SDK V3 before 3.10.0 and V2 before 2.257.3 might allow remote actors to achieve code execution in the target SageMaker execution environment and obtain IAM credentials via pre-creation of a predictably named S3 bucket that the SDK uses without ownership validation. To remediate this issue, users should upgrade to Amazon SageMaker Python SDK 3.10.0 (V3) or 2.257.3 (V2).

Affected products (as reported)

Vendor	Product	Versions
AWS	Amazon SageMaker Python SDK	0 – before 2.257.33.0.0 – before 3.10.0

Weakness: CWE-940 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://github.com/aws/sagemaker-python-sdk/releases/tag/v2.257.3 release-notes, patch
https://github.com/aws/sagemaker-python-sdk/releases/tag/v3.10.0 release-notes, patch
https://pypi.org/project/sagemaker/3.10.0/ release-notes, patch
https://pypi.org/project/sagemaker/2.257.3/ release-notes, patch
https://aws.amazon.com/security/security-bulletins/2026-142-aws/ vendor-advisory
https://github.com/aws/sagemaker-python-sdk/security/advisories/GHSA-5rx8-8fr2-f855 third-party-advisory