MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, UnsafeBlitFormatterBase<T>.Deserialize reads an attacker-controlled byteLength from an extension payload and allocates an array based on that value before validating it against the extension header length or remaining payload bytes. The outer extension header is bounded by available input, but that bound is not used to constrain the inner byteLength before allocation. A very small payload can therefore request a very large T[] allocation. This vulnerability is fixed in 2.5.301 and 3.1.7.
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History
Wed, 24 Jun 2026 16:45:00 +0000
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Messagepack
Messagepack messagepack-csharp |
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Messagepack
Messagepack messagepack-csharp |
Tue, 23 Jun 2026 13:30:00 +0000
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ssvc
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Mon, 22 Jun 2026 22:00:00 +0000
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| Description | MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, UnsafeBlitFormatterBase<T>.Deserialize reads an attacker-controlled byteLength from an extension payload and allocates an array based on that value before validating it against the extension header length or remaining payload bytes. The outer extension header is bounded by available input, but that bound is not used to constrain the inner byteLength before allocation. A very small payload can therefore request a very large T[] allocation. This vulnerability is fixed in 2.5.301 and 3.1.7. | |
| Title | MessagePack-CSharp: Unity unsafe blit formatter allocates from unbounded byte length | |
| Weaknesses | CWE-770 | |
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cvssV4_0
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-06-22T21:11:35.224Z
Updated: 2026-06-25T15:23:26.175Z
Reserved: 2026-05-21T16:18:10.618Z
Link: CVE-2026-48514
Updated: 2026-06-23T12:13:18.495Z
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