# CVE-2026-1778: PYSEC-2026-1888 - SageMaker Python SDK has Exposed HMAC

Source: https://junglewise.ai/threats/cve-2026-1777-aws-sagemaker-python-sdk-hmac-disclosure-and-insecure-tls  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-07. Updated: 2026-05-15  
License: CC BY 4.0 with a link back

CVE-2026-1778 · Severity: high · CVSS 3.1 · Published 2026-07-07

The SageMaker Python SDK, used for building and deploying machine learning models on AWS, contains two security vulnerabilities. One flaw allows users with specific permissions to steal secret keys and tamper with data stored in Amazon S3, while the other disables secure encrypted connections (SSL/TLS), potentially allowing attackers to intercept or modify data during model downloads. These issues could lead to unauthorized data modification or the compromise of sensitive machine learning assets.

Technologies: [Amazon AWS](https://junglewise.ai/threats/technologies/aws), [sagemaker (PyPI)](https://junglewise.ai/threats/technologies/pypi-sagemaker). Vendors: [Amazon](https://junglewise.ai/threats/vendors/amazon), [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-1778 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-1778 being exploited in the wild.

**How severe is CVE-2026-1778?** High severity, with a CVSS score of 3.1, published 7 July 2026.

**Which products and versions are affected?** sagemaker (PyPI) ECOSYSTEM:introduced=0,fixed=2.256.0,introduced=3.0,fixed=3.2.0, ECOSYSTEM:introduced=3.0,fixed=3.2.0.

**Is there a fix for CVE-2026-1778?** Yes. sagemaker (PyPI): upgrade to 3.2.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-1778 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-1778?** Check whether you run Amazon AWS or sagemaker (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- sagemaker (PyPI): upgrade to 3.2.0 or later

  ```sh
  pip install "sagemaker>=3.2.0"
  ```


## Technical details

Two vulnerabilities were identified in the SageMaker Python SDK. CVE-2026-1777 involves the exposure of per-job HMAC keys through environment variables accessible via the DescribeTrainingJob API; an attacker with sufficient IAM permissions can retrieve these keys to forge serialized payloads and overwrite S3 objects. CVE-2026-1778 is a flaw where SSL certificate verification was globally disabled in the Triton Python backend to bypass errors during model downloads, exposing all HTTPS traffic to man-in-the-middle (MitM) attacks. The HMAC issue is resolved in versions 2.256.0 and 3.2.0, while the TLS issue is resolved in 2.256.0 and 3.1.1.

## Affected products

- AWS SageMaker Python SDK v2 < v2.256.0, v3 < v3.2.0

## Identifiers

- CVE-2026-1778
- CVE-2026-1777
- GHSA-rjrp-m2jw-pv9c
- PYSEC-2026-1888

## Timeline

- 2026-02-02: disclosed
- 2026-02-02: advisory

## References

- [https://aws.amazon.com/security/security-bulletins/rss/2026-004-aws/](https://aws.amazon.com/security/security-bulletins/rss/2026-004-aws/)

## Related threats

- [An untrusted search path issue in Aurora PostgreSQL dialect detection in the AWS Advanced Go Wrapper from release 2026-04-06 (awssql/v2.0.0)](https://junglewise.ai/threats/cve-2026-126793-privilege-escalation-in-aurora-postgresql-dialect-detection-in)
- [AWS SDK for pandas EMR unverified bucket ownership](https://junglewise.ai/threats/cve-2026-127119-unverified-ownership-of-the-default-emr-cluster-log-location-in)
- [Amazon mcp-gateway-registry server-side request forgery in registration API](https://junglewise.ai/threats/cve-2026-125926-server-side-request-forgery-in-the-server-registration-and)
- [Amazon mcp-gateway-registry authorization bypass in management API](https://junglewise.ai/threats/cve-2026-100307-missing-authorization-on-the-external-management-api-in-mcp)
- [AWS Kiro CLI incorrect default permissions on session files](https://junglewise.ai/threats/cve-2026-124848-incorrect-default-permissions-on-session-transcripts-and-prompt)