CVE-2026-48509 (GCVE-0-2026-48509)
Vulnerability from cvelistv5
Published
2026-06-22 21:16
Modified
2026-06-25 15:02
CWE
  • CWE-1188 - Insecure Default Initialization of Resource
Summary
MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, the parameterless MessagePackInputFormatter() constructor uses default serializer options, which resolve to MessagePackSerializerOptions.Standard with MessagePackSecurity.TrustedData. The formatter is designed for ASP.NET Core MVC request bodies, which commonly cross an HTTP trust boundary. This insecure default can expose applications to denial-of-service attacks that MessagePackSecurity.UntrustedData is intended to mitigate, such as hash-collision attacks against dictionary-like model properties. This vulnerability is fixed in 2.5.301 and 3.1.7.
Impacted products
Vendor Product Version
MessagePack-CSharp MessagePack-CSharp Version: >= 3.0, < 3.1.7
Version: < 2.5.301
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Show details on NVD website


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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
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