CVE-2026-104002: Fail-open error handling in the data masking utility in Powertools for AWS Lambda (Python)

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-01 · updated 2026-10-02
Weakness: CWE-390

Description

A fail-open error handling issue within the data masking utility of Powertools for AWS Lambda (Python) might allow actors to read sensitive field values that the application intended to mask. To remediate this issue, users should upgrade to version 3.35.0.

Affected products

AWS powertools-lambda-python: from 3.6.0 through 3.34.0

References

https://aws.amazon.com/security/security-bulletins/2026-123-aws/
https://github.com/aws-powertools/powertools-lambda-python/releases/tag/v3.35.0
https://github.com/aws-powertools/powertools-lambda-python/security/advisories/GHSA-3vxg-4xv2-jfh5

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