CVE-2026-6550
Key commitment policy bypass via shared key cache in AWS Encryption SDK for Python
CVSS Score
4.7
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-757 |
| Vendor | aws |
| Product | aws encryption sdk for python |
| Published | Apr 20, 2026 |
| Last Updated | Apr 20, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
Affected Versions
AWS / AWS Encryption SDK for Python
2 ≤ 2.5.1 3 ≤ 3.3.0 4 ≤ 4.0.4
References
aws.amazon.com: https://aws.amazon.com/security/security-bulletins/2026-017-aws/ github.com: https://github.com/aws/aws-encryption-sdk-python/releases/tag/v4.0.5 github.com: https://github.com/aws/aws-encryption-sdk-python/releases/tag/v3.3.1 github.com: https://github.com/aws/aws-encryption-sdk-python/security/advisories/GHSA-v638-38fc-rhfv
Credits
1seal.org