CVE-2026-6550
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.
- Published Apr 20, 2026
- CVSS 5.7 medium
- 0.1% chance of exploitation in the next 30 days (EPSS)
- A fix is available
Affected software
In the news
- CVE-2026-6550 - Key commitment policy bypass via shared key cache in AWS Encryption SDK for Python AWS Security Bulletins ·