The Global Unverify: How One Line of Python Broke SageMaker TLS
Vulnerability ID: CVE-2026-1778
CVSS Score: 5.9
Published: 2026-02-02
Developers hate SSL errors. They hate them so much that sometimes, rather than fixing the certificate chain, they simply turn off validation for the entire process. This is exactly what happened in the Amazon SageMaker Python SDK. A 'quick fix' to suppress errors from the ssl library resulted in a global disablement of certificate verification, leaving machine learning pipelines wide open to Man-in-the-Middle (MitM) attacks and malicious model injection.
TL;DR
The Amazon SageMaker Python SDK (< 3.1.1, < 2.256.0) globally disabled SSL certificate verification to suppress errors when downloading models. This allows attackers to intercept HTTPS traffic, inject malicious models, and achieve Remote Code Execution (RCE) via insecure deserialization.
⚠️ Exploit Status: POC
Technical Details
- CWE ID: CWE-295
- Attack Vector: Network (MitM)
- CVSS v3.1: 5.9 (Medium)
- Impact: Integrity Loss / Remote Code Execution
- Root Cause: Global SSL Context Monkeypatching
- KEV Status: Not Listed
Affected Systems
- Amazon SageMaker Python SDK v3.x < 3.1.1
- Amazon SageMaker Python SDK v2.x < 2.256.0
- Triton Inference Server integrations via SageMaker
-
SageMaker Python SDK: < 3.1.1 (Fixed in:
3.1.1) -
SageMaker Python SDK: < 2.256.0 (Fixed in:
2.256.0)
Code Analysis
Commit: 5e7a3ef
Removed global ssl unverified context override
- ssl._create_default_https_context = ssl._create_unverified_context
Exploit Details
- Hypothetical: Standard MitM attack injecting a malicious Pickle file during model download.
Mitigation Strategies
- Update SageMaker Python SDK to patched versions immediately.
- Audit codebase for other instances of
ssl._create_unverified_context. - Implement network segmentation to reduce MitM risks.
Remediation Steps:
- Run
pip install --upgrade sagemakerto ensure you are on version 3.1.1+ or 2.256.0+. - If using custom containers, rebuild them to include the updated SDK version.
- Verify that
ssl._create_default_https_contexthas not been modified in your own startup scripts.
References
Read the full report for CVE-2026-1778 on our website for more details including interactive diagrams and full exploit analysis.
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