CVE-2026-6550

MEDIUM EPSS 0.9%
Published Apr 20, 20262mo ago · Modified Jun 17, 20262w ago
5.7 CVSS 4.0
Medium
Find Similar
Published Apr 20, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
5.7
Exploitability
—
Impact
—
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Local
Attack Complexity High
Privileges Required Low
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
0.9% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-757

References 4

  • 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/v3.3.1
  • 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/security/advisories/GHSA-v638-38fc-rhfv

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.