CVE-2026-49451

Summary

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 Software

VendorProductVersion RangeStatus
microsoftOpenAPI.NET>= 2.0.0-preview11, < 2.7.5affected
microsoftOpenAPI.NET>= 3.0.0, < 3.5.4affected

Weaknesses

  • CWE-674: CWE-674: Uncontrolled Recursion

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: yes
    • Technical Impact: partial

Additional References

References