messagepack 関連製品全体の CVE とセキュリティ脆弱性情報を集約し、CVSS、EPSS、公開日、脆弱性情報データを掲載しています。
過去の問題は主に vendor risk memory corruption and vendor risk input validation などに関し、一部は アプリケーションクラッシュ を招き、vendor surface production workloads and vendor surface software deployment 関連の場面に影響します。
掲載データは公開脆弱性情報とセキュリティ公告に基づき、過去の暴露面と修補優先度の評価に利用できます。
| CVE | 概要 | ソース | CVSS 最大値 | EPSS（%） | 公開 | 更新 |
|---|---|---|---|---|---|---|
| CVE-2026-48517 | MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePack-CSharp's typeless deserialization includes MessagePackSerializerOptions.ThrowIfDeserializingTypeIsDisallowed(Type) as a safety check for dangerous types. The default implementation checks the outer type name, but it does not recursively inspect array element types or generic type arguments. As a result, a type that would be blocked directly can be wrapped inside an array or constructed generic type and | [email protected] | 6.3 | 0.25% | 2026-06-22 | 2026-06-25 |
| CVE-2026-48516 | MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, InterfaceLookupFormatter<TKey,TElement> constructs an internal Dictionary<TKey, IGrouping<TKey,TElement>> with the default equality comparer instead of the security-aware comparer supplied by options.Security.GetEqualityComparer<TKey>(). This formatter omission allows hash-collision CPU denial of service against ILookup<TKey,TElement> even when the application has opted into the untrusted-data security posture Thi | [email protected] | 6.3 | 0.21% | 2026-06-22 | 2026-06-25 |
| CVE-2026-48515 | MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePack-CSharp's multi-dimensional array formatters read dimension lengths directly from the payload and allocate T[,], T[,,], or T[,,,] before validating that the dimension product matches the encoded element count. The formatter reads a guarded element array header, but allocation of the target multi-dimensional array happens before the dimensions are checked against that element count. A small payload can t | [email protected] | 6.3 | 0.21% | 2026-06-22 | 2026-06-25 |
| CVE-2026-48514 | 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 v | [email protected] | 6.3 | 0.21% | 2026-06-22 | 2026-06-25 |
| CVE-2026-48513 | MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, runtime-generated union deserializers emitted by DynamicUnionResolver do not call MessagePackSecurity.DepthStep(ref reader) and do not decrement reader.Depth around recursive deserialization and skip paths. This means union deserialization does not consistently participate in the maximum object graph depth enforcement that protects other recursive formatter paths. For unknown union keys, the emitted deserializer c | [email protected] | 6.3 | 0.21% | 2026-06-22 | 2026-06-25 |
| CVE-2026-48512 | MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePack-CSharp's JSON conversion helpers contain multiple recursion paths that do not consistently enforce a depth limit. These paths are in the JSON conversion component rather than normal typed MessagePack deserialization. MessagePackSerializer.ConvertFromJson recursively processes nested JSON arrays and objects in FromJsonCore() without consulting MessagePackSecurity.MaximumObjectGraphDepth. TinyJsonReader. | [email protected] | 6.3 | 0.21% | 2026-06-22 | 2026-06-25 |
| CVE-2026-48511 | MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, ExpandoObjectFormatter.Deserialize populates System.Dynamic.ExpandoObject by calling IDictionary<string, object>.Add for each map entry. ExpandoObject internally maintains member names in array-like structures, so inserting many distinct keys can require repeated linear scans and array copies. For large attacker-controlled maps, this produces quadratic CPU and allocation behavior. The issue is especially surprisin | [email protected] | 6.3 | 0.21% | 2026-06-22 | 2026-06-25 |
| CVE-2026-48510 | MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, when MessagePack-CSharp decompresses Lz4Block or Lz4BlockArray payloads, it reads declared uncompressed lengths from the wire and allocates output buffers based on those lengths before validating that the compressed data is valid or that the declared expansion is reasonable. A small payload can claim a very large uncompressed length and force a large allocation before LZ4 decoding begins. This vulnerability is fix | [email protected] | 6.3 | 0.23% | 2026-06-22 | 2026-06-25 |
| CVE-2026-48509 | 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 | [email protected] | 6.3 | 0.23% | 2026-06-22 | 2026-06-25 |
| CVE-2026-48506 | MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePackReader.TrySkip() recursively descends into nested arrays and maps without incrementing the reader depth or calling the configured depth checks. This bypasses MessagePackSecurity.MaximumObjectGraphDepth, the library's documented protection against deeply nested object graphs. Many generated and dynamic formatters call reader.Skip() when they encounter unknown map keys, unknown array members, ignored fiel | [email protected] | 7.5 | 0.29% | 2026-06-22 | 2026-06-23 |
| CVE-2026-48502 | MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePackReader.ReadDateTime() can allocate stack memory based on an attacker-controlled MessagePack extension length. In the slow path for timestamp extension parsing, the computed tokenSize includes the extension body length from the wire and is used in a stackalloc operation before the extension length is validated as one of the valid timestamp sizes. A very small payload can claim a large timestamp extension | [email protected] | 8.2 | 0.26% | 2026-06-22 | 2026-06-23 |
| CVE-2026-48109 | MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, A vulnerability exists in the optional LZ4 decompression path used by MessagePack compression modes Lz4Block and Lz4BlockArray. The decoder implementation is based on a deprecated fast-decompression algorithm that does not take a source-length bound. A remote attacker can send a crafted MessagePack payload with manipulated LZ4 token/length fields to force out-of-bounds reads from the compressed input buffer. In af | [email protected] | 8.2 | 0.30% | 2026-06-22 | 2026-06-23 |
| CVE-2020-5234 | MessagePack for C# and Unity before version 1.9.11 and 2.1.90 has a vulnerability where untrusted data can lead to DoS attack due to hash collisions and stack overflow. Review the linked GitHub Security Advisory for more information and remediation steps. | [email protected] | 4.8 | 1.58% | 2020-01-31 | 2026-06-16 |