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 calls reader.Skip() on attacker-controlled data without an enclosing depth step. This vulnerability is fixed in 2.5.301 and 3.1.7.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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 calls
    reader.Skip() on attacker-controlled data without an enclosing depth step. This vulnerability is fixed in
    2.5.301 and 3.1.7. (CVE-2026-48513)

ID	Name	Product	Family	Type	Severity
463012	Echo: MessagePack: security update to 2.5.172+echo.1	Tenable Cloud Security	Echo Local Security Checks	Local	medium
463012	Echo: MessagePack: security update to 2.5.172+echo.1	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	medium
443959	SCA: security update for MessagePack (GHSA-wfr3-xj75-pfwh)	Tenable Cloud Security	SCA Checks	Local	medium
443959	SCA: security update for MessagePack (GHSA-wfr3-xj75-pfwh)	Tenable Self-Hosted Container Security	SCA Checks	Local	medium

Detections

Analytics

CVE-2026-48513

medium

Tenable Plugins

medium

medium

medium

medium