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.
History

Wed, 22 Apr 2026 12:15:00 +0000

Type Values Removed Values Added
First Time appeared Amazon
Amazon aws Encryption Sdk For Python
Vendors & Products Amazon
Amazon aws Encryption Sdk For Python

Mon, 20 Apr 2026 20:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 20 Apr 2026 19:45:00 +0000

Type Values Removed Values Added
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.
Title Key commitment policy bypass via shared key cache in AWS Encryption SDK for Python
Weaknesses CWE-757
References
Metrics cvssV3_1

{'score': 4.7, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N'}

cvssV4_0

{'score': 5.7, 'vector': 'CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: AMZN

Published:

Updated: 2026-04-20T19:44:11.685Z

Reserved: 2026-04-17T20:06:20.299Z

Link: CVE-2026-6550

cve-icon Vulnrichment

Updated: 2026-04-20T19:44:07.480Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-20T20:16:49.283

Modified: 2026-04-21T16:20:24.180

Link: CVE-2026-6550

cve-icon Redhat

No data.