Skip to content

CVE-2026-48514 (Low) detected in messagepack.3.1.4.nupkg #45

Description

@mend-bolt-for-github

CVE-2026-48514 - Low 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, UnsafeBlitFormatterBase.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 very large T[] allocation. This vulnerability is fixed in 2.5.301 and 3.1.7.

Publish Date: 2026-06-22

URL: CVE-2026-48514

CVSS 3 Score Details (3.7)

Base Score Metrics:

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

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Origin: GHSA-w567-gjr2-hm5j

Release Date: 2026-06-22

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


Step up your Open Source Security Game with Mend here

Metadata

Metadata

Assignees

No one assigned

    Projects

    No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions