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 fields, or data that should be skipped for forward compatibility. A deeply nested value in one of these skipped positions can therefore cause unbounded recursion and an uncatchable StackOverflowException. 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,
    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 fields, or data that should be skipped for forward compatibility. A
    deeply nested value in one of these skipped positions can therefore cause unbounded recursion and an
    uncatchable StackOverflowException. This vulnerability is fixed in 2.5.301 and 3.1.7. (CVE-2026-48506)

ID	Name	Product	Family	Type	Severity
459490	Echo: MessagePack: security update to 2.5.172+echo.1	Tenable Cloud Security	Echo Local Security Checks	Local	high
459490	Echo: MessagePack: security update to 2.5.172+echo.1	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	high
443971	SCA: security update for MessagePack (GHSA-vh6j-jc39-fggf)	Tenable Cloud Security	SCA Checks	Local	high
443971	SCA: security update for MessagePack (GHSA-vh6j-jc39-fggf)	Tenable Self-Hosted Container Security	SCA Checks	Local	high

Detections

Analytics

CVE-2026-48506

high

Tenable Plugins

high

high

high

high