CVE-2025-3857: Amazon Ion Dotnet

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

When reading binary Ion data through Amazon.IonDotnet using the RawBinaryReader class, Amazon.IonDotnet does not check the number of bytes read from the underlying stream while deserializing the binary format. If the Ion data is malformed or truncated, this triggers an infinite loop condition that could potentially result in a denial of service. Users should upgrade to Amazon.IonDotnet version 1.3.1 and ensure any forked or derivative code is patched to incorporate the new fixes.

Affected products

• Amazon Amazon Ion Dotnet: before 1.3.1 (fixed in 1.3.1)

Published 2025-04-21. Last modified 2026-06-17.