Information Exposure

Overview Amazon.Extensions.S3.Encryption is an easy-to-use Amazon S3 encryption client that allows you to secure your sensitive data before you send it to Amazon S3. Affected versions of this package are vulnerable to Information Exposure via manipulation of the object's metadata to downgrade the...

CVE-2026-110310

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...

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...

CVE-2026-110310: Observable Response Discrepancy

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...

PT-2026-114031

Name of the Vulnerable Software and Affected Versions S3 .NET Encryption Client versions prior to 3.2.2 S3 .NET Encryption Client versions prior to 4.0.3 Description A padding oracle flaw exists in the S3 .NET Encryption Client. A remote user with read access to encrypted objects in an S3 bucket...

Nextcloud: Improper confidentiality protection of server-side encryption keys

This vulnerability is related to the Improper integrity protection of server-side encryption keys vulnerability but leverages a different attack vector. While the previous attack broke the confidentiality of encrypted files because the public keys are not integrity-protected, this new attack brea...