CVE-2026-49451 (High) detected in microsoft.openapi.2.4.1.nupkg

[mend-bolt-for-github]

CVE-2026-49451 - High Severity Vulnerability

Vulnerable Library - microsoft.openapi.2.4.1.nupkg

.NET models with JSON and YAML writers for OpenAPI specification

Library home page: https://api.nuget.org/packages/microsoft.openapi.2.4.1.nupkg

Sample Path to Dependency File: /src/SharpConnector.Api/SharpConnector.Api.csproj

Path to vulnerable library: /home/wss-scanner/.nuget/packages/microsoft.openapi/2.4.1/microsoft.openapi.2.4.1.nupkg

Dependency Hierarchy:

• swashbuckle.aspnetcore.10.1.7.nupkg (Root Library)
  • swashbuckle.aspnetcore.swaggergen.10.1.7.nupkg
    • swashbuckle.aspnetcore.swagger.10.1.7.nupkg
      • ❌ microsoft.openapi.2.4.1.nupkg (Vulnerable Library)

Found in base branch: main

Vulnerability Details

The OpenAPI.NET SDK contains a useful object model for OpenAPI documents in .NET along with common serializers to extract raw OpenAPI JSON and YAML documents from the model. From 2.0.0-preview11 until 2.7.5 and 3.5.4, a small OpenAPI document containing a circular schema reference can cause process termination through stack overflow in Microsoft.OpenApi. The issue affects OpenAPI document parsing through public OpenAPI.NET reader APIs and has been confirmed across both JSON and YAML reader paths. This vulnerability is fixed in 2.7.5 and 3.5.4.

Publish Date: 2026-06-30

URL: CVE-2026-49451

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-v5pm-xwqc-g5wc

Release Date: 2026-06-30

Fix Resolution: microsoft.openapi - 2.7.5,microsoft.openapi - 3.5.4

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