Description
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 pass the outer type check. The formatter machinery can then materialize formatters for the inner blocked type. This vulnerability is fixed in 2.5.301 and 3.1.7.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| MessagePack-CSharp | MessagePack-CSharp | >= 3.0, < 3.1.7, < 2.5.301 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | python-msgpack | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| NuGet | MessagePack | < 2.5.301 | 2.5.301 | GHSA-qhmf-xw27-6rqr |
| NuGet | MessagePack | >= 3.0, < 3.1.7 | 3.1.7 | GHSA-qhmf-xw27-6rqr |