AWS Security Bulletins: CVE-2026-83551 - Cleartext storage of HMAC signing key in Amazon SageMaker Python SDK
AWS Security Bulletins has published a new security advisory. Here is a summary and what to do.
Key points
- New advisory from AWS Security Bulletins.
- Review affected versions in the advisory.
- Apply updates promptly.
AWS Security Bulletins published a security advisory titled “CVE-2026-83551 - Cleartext storage of HMAC signing key in Amazon SageMaker Python SDK”.
At a glance
- Publisher
- AWS Security Bulletins
- CVEs
- CVE-2026-83551
What the advisory says
Bulletin ID: 2026-093-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 09/01/2026 11:00 AM PDT Description: SageMaker Python SDK's @step and @remote decorator pipeline component uses an HMAC key to protect the integrity of serialized function payloads stored in S3. We identified an issue where the HMAC secret key is stored in cleartext within pipeline definitions and accessible via the DescribePipeline API. This allows an actor with a role in that account that has permissions to invoke DescribePipeline to extract the key, create cloud-pickled payloads with valid HMACs, and overwrite S3 objects, achieving code execution in another user's pipeline execution context within the same AWS account. Impacted versions: - HMAC Configuration in SageMaker Python SDK v3 < v3.11.0 - HMAC Configuration in SageMaker Python SDK v2 < v2.256.0 Please refer to the article below
What should you do?
- Read the full vendor advisory linked below and confirm whether you run affected versions.
- Schedule the recommended update, prioritising internet-facing systems.
- Watch for exploitation reports; unpatched edge devices are frequent targets.
What to do and how to stay safe: CVE-2026-83551
- Vulnerability severity scores ignore your specific architecture and context.
- Exploitability depends on network exposure and user behavior, not just code flaws.
- Prioritization requires continuous asset inventory and threat intelligence alignment.
Risk-based vulnerability management focuses your limited resources on the flaws that actually threaten your business. Start by mapping your critical assets and checking for active exploits to prioritize your backlog.
Step-by-step guide: Risk-Based Vulnerability Management: Prioritize Fixes by Actual Danger
General security guidance from the Threat Times newsroom. It is not confirmed advice from the organisations named in this story.
