CVE-2026-112408: CWE-940 Improper verification of source of a communication channel in AWS Amazon SageMaker Python SDK
Description
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
CVSS v3.1
Score 8.1high
Affected software
AWS
Amazon SageMaker Python SDK
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-112408 in the Amazon SageMaker Python SDK arises from missing verification of the source of a communication channel in the default_bucket() function. This flaw allows an attacker to pre-create an S3 bucket with a predictable name that the SDK uses without validating ownership. Exploiting this, an attacker could execute arbitrary code in the SageMaker execution environment and obtain IAM credentials. The issue affects SDK versions prior to 3.10.0 in V3 and prior to 2.257.3 in V2. AWS has published an advisory and released patched versions to remediate the vulnerability.
Potential Impact
Successful exploitation can lead to remote code execution within the target SageMaker environment and unauthorized access to IAM credentials, which may result in full compromise of AWS resources accessible by those credentials. The CVSS score of 8.1 reflects high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
AWS has released patched versions 3.10.0 (V3) and 2.257.3 (V2) of the Amazon SageMaker Python SDK to fix this vulnerability. Users should upgrade to these versions or later to remediate the issue. Since this is a cloud-hosted service, AWS manages the underlying infrastructure, but client-side SDK updates are required to prevent exploitation. No other mitigations are specified in the vendor advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- AMZN
- Date Reserved
- 2026-10-19T17:00:36.100Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Is Cloud Service
- true
- Vendor Advisory Urls
- [{"url":"https://aws.amazon.com/security/security-bulletins/2026-142-aws/","vendor":"AWS"}]
Threat ID: 6ad916a44d27ba8daaf52973
Added to database: 10/21/2026, 19:46:44 UTC
Last enriched: 10/21/2026, 20:00:28 UTC
Last updated: 10/22/2026, 03:34:05 UTC
Views: 10
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