CVE-2026-8596: CWE-312 Cleartext storage of sensitive information in Amazon SageMaker Python SDK AWS
Bulletin ID: 2026-031-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 05/14/2026 13:00 PM PDT Description: Amazon SageMaker Python SDK is an open-source library for training and deploying machine learning models on Amazon SageMaker. The ModelBuilder component simplifies model deployment by automating model artifact preparation and SageMaker model creation. We identified two issues affecting the model artifact integrity verification mechanism in the ModelBuilder/Serve component: - CVE-2026-8596: We identified a cleartext storage of sensitive information issue in the ModelBuilder/Serve component. When building models using ModelBuilder, the SDK stored an HMAC signing key as a container environment variable (SAGEMAKER_SERVE_SECRET_KEY). This key was returned in plaintext by SageMaker describe APIs (DescribeModel, DescribeEndpointConfig, DescribeModelPackage). A remote authenticated actor with permissions to call these APIs and S3 write access to the model artifact path could extract the key, forge valid integrity signatures for specially crafted model artifacts, and achieve code execution in inference containers. - CVE-2026-8597: We identified a missing integrity verification issue in the Triton inference handler. The Triton handler deserialized model artifacts without performing integrity verification before execution. A remote authenticated actor with S3 write access to the model artifact path could replace model artifacts with a specially crafted pickle payload that would be deserialized without verification, achieving code execution in inference containers. Impacted versions: Amazon SageMaker Python SDK >= v2.199.0 AND = v3.0.0 AND <= v3.7.1 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-8596) affects Amazon SageMaker Python SDK versions prior to v2.257.2 and v3.8.0. The issue is cleartext storage of sensitive information, specifically the HMAC signing key, in the ModelBuilder/Serve component. An authenticated user with specific permissions can extract this key from API responses and use it to forge integrity signatures, which may allow code execution within inference containers. AWS manages the SageMaker service as a cloud service and has released patched SDK versions to address this issue. Users are advised to upgrade the SDK and rebuild models to mitigate the risk.
Potential Impact
The vulnerability allows an authenticated user with certain permissions to obtain the HMAC signing key in cleartext. This can enable forging of integrity signatures, potentially leading to unauthorized code execution within inference containers. The CVSS score of 7.2 reflects high impact on confidentiality, integrity, and availability. There are no known exploits in the wild at this time.
Mitigation Recommendations
AWS has released patched versions of the Amazon SageMaker Python SDK (v2.257.2 and later, v3.8.0 and later) that address this vulnerability. Users should upgrade to these versions and rebuild affected models to mitigate the risk. Since this is a cloud service, AWS manages remediation on the service side, but client-side SDK upgrades and model rebuilds are required. Refer to the official AWS security bulletin at https://aws.amazon.com/security/security-bulletins/2026-031-aws/ for detailed guidance.
CVE-2026-8596: CWE-312 Cleartext storage of sensitive information in Amazon SageMaker Python SDK AWS
Description
Bulletin ID: 2026-031-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 05/14/2026 13:00 PM PDT Description: Amazon SageMaker Python SDK is an open-source library for training and deploying machine learning models on Amazon SageMaker. The ModelBuilder component simplifies model deployment by automating model artifact preparation and SageMaker model creation. We identified two issues affecting the model artifact integrity verification mechanism in the ModelBuilder/Serve component: - CVE-2026-8596: We identified a cleartext storage of sensitive information issue in the ModelBuilder/Serve component. When building models using ModelBuilder, the SDK stored an HMAC signing key as a container environment variable (SAGEMAKER_SERVE_SECRET_KEY). This key was returned in plaintext by SageMaker describe APIs (DescribeModel, DescribeEndpointConfig, DescribeModelPackage). A remote authenticated actor with permissions to call these APIs and S3 write access to the model artifact path could extract the key, forge valid integrity signatures for specially crafted model artifacts, and achieve code execution in inference containers. - CVE-2026-8597: We identified a missing integrity verification issue in the Triton inference handler. The Triton handler deserialized model artifacts without performing integrity verification before execution. A remote authenticated actor with S3 write access to the model artifact path could replace model artifacts with a specially crafted pickle payload that would be deserialized without verification, achieving code execution in inference containers. Impacted versions: Amazon SageMaker Python SDK >= v2.199.0 AND = v3.0.0 AND <= v3.7.1 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.
CVSS v3.1
Score 7.2high
Affected software
Amazon SageMaker Python SDK
AWS
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-8596) affects Amazon SageMaker Python SDK versions prior to v2.257.2 and v3.8.0. The issue is cleartext storage of sensitive information, specifically the HMAC signing key, in the ModelBuilder/Serve component. An authenticated user with specific permissions can extract this key from API responses and use it to forge integrity signatures, which may allow code execution within inference containers. AWS manages the SageMaker service as a cloud service and has released patched SDK versions to address this issue. Users are advised to upgrade the SDK and rebuild models to mitigate the risk.
Potential Impact
The vulnerability allows an authenticated user with certain permissions to obtain the HMAC signing key in cleartext. This can enable forging of integrity signatures, potentially leading to unauthorized code execution within inference containers. The CVSS score of 7.2 reflects high impact on confidentiality, integrity, and availability. There are no known exploits in the wild at this time.
Mitigation Recommendations
AWS has released patched versions of the Amazon SageMaker Python SDK (v2.257.2 and later, v3.8.0 and later) that address this vulnerability. Users should upgrade to these versions and rebuild affected models to mitigate the risk. Since this is a cloud service, AWS manages remediation on the service side, but client-side SDK upgrades and model rebuilds are required. Refer to the official AWS security bulletin at https://aws.amazon.com/security/security-bulletins/2026-031-aws/ for detailed guidance.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- AMZN
- Date Reserved
- 2026-05-14T13:39:22.096Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Is Cloud Service
- true
- Vendor Advisory Urls
- [{"url":"https://aws.amazon.com/security/security-bulletins/2026-031-aws/","vendor":"AWS"}]
Threat ID: 6a062b6cec166c07b00def7e
Added to database: 05/14/2026, 20:07:08 UTC
Last enriched: 06/08/2026, 22:16:54 UTC
Last updated: 09/13/2026, 22:01:38 UTC
Views: 157
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