CVE-2026-110310: fallo de gravedad media en Amazon.Extensions.S3.Encryption
RSA PKCS#1 v1.5 padding oracle via legacy envelope key format downgrade in Amazon S3 Encryption Client for .NET
Publicada el
Aviso por correo cuando entre en el KEV, tenga PoC pública o suba de nota.
13Vexday Risk Score
Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.
ssvc Trackcvss 6epss 0.5%
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 PKCS#1 v1.5. Since this padding scheme is susceptible to the well-known Bleichenbacher attack, the user can use a PKCS#1 v1.5 padding oracle to recover the RSA-wrapped envelope key and decrypt the object.
To remediate this issue, we recommend that users upgrade to version 3.2.2 or 4.0.3. The 1.x and 2.x lines will not be patched, users of those lines need to migrate to 3.2.2 or 4.0.3.
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Productos afectados
Amazon · Amazon.Extensions.S3.EncryptionReferencias
https://aws.amazon.com/security/security-bulletins/2026-135-aws/https://github.com/aws/amazon-s3-encryption-client-dotnet/security/advisories/GHSA-322w-f6rw-r4fjhttps://www.nuget.org/packages/Amazon.Extensions.S3.Encryption/3.2.2https://www.nuget.org/packages/Amazon.Extensions.S3.Encryption/4.0.3