EUVD-2026-101618

A remote user who can read encrypted objects in the S3 bucket can force a padding downgrade by altering the padding scheme recorded in an object's metadata to legacy PKCS1 v1.5. Since this padding scheme is susceptible to the well-known Bleichenbacher attack, the user can use a PKCS1 v1.5 padding...

CVE-2026-110310

The Amazon S3 Encryption Client for .NET is vulnerable to an RSA PKCS#1 v1.5 padding oracle attack. A remote user capable of reading encrypted objects in an S3 bucket can force a padding downgrade by modifying an object's metadata to use the legacy PKCS#1 v1.5 scheme. This vulnerability allows th...