Skip to content
CVE PROGRAM SOURCE RECORD7.5 High

CVE-2026-49451

Microsoft.OpenAPI: Circular schema references may terminate OpenAPI parsing

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

microsoft OpenAPI.NET

  • >= 2.0.0-preview11, < 2.7.5affected
  • >= 3.0.0, < 3.5.4affected

References