CVE-2026-1777
Published: 02 February 2026
Summary
CVE-2026-1777 is a high-severity Cleartext Transmission of Sensitive Information (CWE-319) vulnerability in Amazon SageMaker Python (inferred from references). Its CVSS base score is 7.2 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Unsecured Credentials (T1552); ranked at the 5.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Role-based training covers secure transmission methods, mitigating cleartext transmission of sensitive data.
By requiring documented security controls for information exchanges, the control reduces the risk of cleartext transmission of sensitive data.
Mapping transmission actions in data flows helps prevent cleartext transmission of sensitive information.
Settings can enforce secure transmission protocols to prevent cleartext transmission of sensitive data.
Policy addresses secure transport and handling of media to avoid cleartext transmission of sensitive information.
Enforces safeguards against cleartext transmission of CUI when data leaves organizational boundaries to external systems.
Explicit controls and continuous oversight on external system services prevent cleartext transmission of sensitive information over provider-managed channels.
Key-establishment procedures specify secure distribution channels that preclude cleartext transmission of key material.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
HMAC key exposure directly matches T1552 (Unsecured Credentials); attacker use of key to upload/poison S3 artifacts matches T1565.001 (Stored Data Manipulation) and T1105 (Ingress Tool Transfer) leading to automatic execution in training jobs.
NVD Description
The Amazon SageMaker Python SDK before v3.2.0 and v2.256.0 includes the ModelBuilder HMAC signing key in the cleartext response elements of the DescribeTrainingJob function. A third party with permissions to both call this API and permissions to modify objects in…
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the Training Jobs S3 output location may have the ability to upload arbitrary artifacts which are executed the next time the Training Job is invoked.
Deeper analysisAI
CVE-2026-1777 is a vulnerability in the Amazon SageMaker Python SDK versions prior to v3.2.0 and v2.256.0, where the ModelBuilder HMAC signing key is exposed in cleartext within the response elements of the DescribeTrainingJob function. This issue, classified under CWE-319 (Cleartext Storage of Sensitive Information), carries a CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H), indicating high impact on confidentiality, integrity, and availability.
Exploitation requires a third party with permissions to invoke the DescribeTrainingJob API and to modify objects in the associated Training Jobs S3 output location. Such an attacker can capture the exposed HMAC key and use it to upload arbitrary artifacts to the S3 bucket, which are then executed automatically upon the next invocation of the Training Job.
AWS security bulletin 2026-004 and the associated GitHub security advisory (GHSA-rjrp-m2jw-pv9c) recommend upgrading to Amazon SageMaker Python SDK v3.2.0 or v2.256.0 as the primary mitigation. Release notes for these versions on GitHub confirm the fixes addressing the cleartext key exposure.
This vulnerability is particularly relevant to AI/ML workflows in AWS SageMaker, where compromised training jobs could lead to arbitrary code execution in machine learning pipelines.
Details
- CWE(s)