CVE-2026-48109 - 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, A vulnerability exists in the optional LZ4 decompression path used by MessagePack compression modes Lz4Block and Lz4BlockArray. The decoder implementation is based on a deprecated fast-decompression algorithm that does not take a source-length bound. A remote attacker can send a crafted MessagePack payload with manipulated LZ4 token/length fields to force out-of-bounds reads from the compressed input buffer. In affected environments, this can trigger an AccessViolationException during decompression, causing process termination (denial of service). Under some conditions, limited unintended memory disclosure from over-read data may also be possible before failure. This vulnerability is fixed in 2.5.301 and 3.1.7.
Publish Date: 2026-06-22
URL: CVE-2026-48109
CVSS 3 Score Details (8.2)
Base Score Metrics:
- Exploitability Metrics:
- Attack Vector: Network
- Attack Complexity: Low
- Privileges Required: None
- User Interaction: None
- Scope: Unchanged
- Impact Metrics:
- Confidentiality Impact: Low
- Integrity Impact: None
- Availability Impact: High
For more information on CVSS3 Scores, click here.
Suggested Fix
Type: Upgrade version
Origin: GHSA-hv8m-jj95-wg3x
Release Date: 2026-06-11
Fix Resolution: messagepack - 2.5.301,messagepack - 3.1.7
Step up your Open Source Security Game with Mend here
CVE-2026-48109 - High Severity Vulnerability
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:
Found in base branch: develop
MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, A vulnerability exists in the optional LZ4 decompression path used by MessagePack compression modes Lz4Block and Lz4BlockArray. The decoder implementation is based on a deprecated fast-decompression algorithm that does not take a source-length bound. A remote attacker can send a crafted MessagePack payload with manipulated LZ4 token/length fields to force out-of-bounds reads from the compressed input buffer. In affected environments, this can trigger an AccessViolationException during decompression, causing process termination (denial of service). Under some conditions, limited unintended memory disclosure from over-read data may also be possible before failure. This vulnerability is fixed in 2.5.301 and 3.1.7.
Publish Date: 2026-06-22
URL: CVE-2026-48109
Base Score Metrics:
- Exploitability Metrics:
- Attack Vector: Network
- Attack Complexity: Low
- Privileges Required: None
- User Interaction: None
- Scope: Unchanged
- Impact Metrics:
- Confidentiality Impact: Low
- Integrity Impact: None
- Availability Impact: High
For more information on CVSS3 Scores, click here.Type: Upgrade version
Origin: GHSA-hv8m-jj95-wg3x
Release Date: 2026-06-11
Fix Resolution: messagepack - 2.5.301,messagepack - 3.1.7
Step up your Open Source Security Game with Mend here