CVE-2026-48506 (High) detected in messagepack.3.1.4.nupkg

[mend-bolt-for-github]

CVE-2026-48506 - High Severity Vulnerability

Vulnerable Library - messagepack.3.1.4.nupkg

Extremely Fast MessagePack(MsgPack) Serializer for C# (.NET Framework, .NET 6, Unity, Xamarin).

Library home page: https://api.nuget.org/packages/messagepack.3.1.4.nupkg

Path to dependency file: /src/SharpConnector.Tests/SharpConnector.Tests.csproj

Path to vulnerable library: /home/wss-scanner/.nuget/packages/messagepack/3.1.4/messagepack.3.1.4.nupkg,/home/wss-scanner/.nuget/packages/messagepack/3.1.4/messagepack.3.1.4.nupkg,/home/wss-scanner/.nuget/packages/messagepack/3.1.4/messagepack.3.1.4.nupkg

Dependency Hierarchy:

• enyimmemcachedcore.3.5.0.nupkg (Root Library)
  • ❌ messagepack.3.1.4.nupkg (Vulnerable Library)

Found in base branch: develop

Vulnerability Details

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.

Publish Date: 2026-06-22

URL: CVE-2026-48506

CVSS 3 Score Details (7.5)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: None
  • Integrity Impact: None
  • Availability Impact: High

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Origin: GHSA-vh6j-jc39-fggf

Release Date: 2026-06-22

Fix Resolution: messagepack - 2.5.301,messagepack - 3.1.7,MessagePack - 3.1.7,MessagePack - 2.5.301

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