CVE-2026-6550

MediumCVSS 4.7/10Last modified Oct 26, 2026

Description

Cryptographic algorithm downgrade in the caching layer of Amazon AWS Encryption SDK for Python before version 3.3.1 and before version 4.0.5 might allow an authenticated local threat actor to bypass key commitment policy enforcement via a shared key cache, resulting in ciphertext that can be decrypted to multiple different plaintexts.

To remediate this issue, users should upgrade to version 3.3.1, 4.0.5 or above.

Metrics

CVSS 3.1 4.7/10CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N

Weakness enumeration

Affected software

Source: the vendor's advisory (CNA). NVD analysis pending.

VendorProductVersions
AWSAWS Encryption SDK for Python>= 2, <= 2.5.1; >= 3, <= 3.3.0; >= 4, <= 4.0.4

References

Timeline

Published
Apr 20, 2026
Last modified
Oct 26, 2026
NVD status
Awaiting Analysis

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CVE-2026-6550: Medium severity, CVSS 4.7 | Vulnix