Medium severity4.7NVD Advisory· Published Apr 20, 2026· Updated Apr 21, 2026
CVE-2026-6550
CVE-2026-6550
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.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
aws-encryption-sdkPyPI | >= 2.0.0, < 3.3.1 | 3.3.1 |
aws-encryption-sdkPyPI | >= 4.0.0, < 4.0.5 | 4.0.5 |
Affected products
1Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
8- github.com/advisories/GHSA-v638-38fc-rhfvghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-6550ghsaADVISORY
- aws.amazon.com/security/security-bulletins/2026-017-awsghsaWEB
- github.com/aws/aws-encryption-sdk-python/releases/tag/v3.3.1nvdWEB
- github.com/aws/aws-encryption-sdk-python/releases/tag/v4.0.5nvdWEB
- github.com/aws/aws-encryption-sdk-python/security/advisories/GHSA-v638-38fc-rhfvnvdWEB
- github.com/google/security-research/security/advisories/GHSA-wqgp-vphw-hphfghsaWEB
- aws.amazon.com/security/security-bulletins/2026-017-aws/nvd
News mentions
0No linked articles in our index yet.