High, CVSS 7.5NuGetPublished
Microsoft.OpenAPI: Circular schema references may terminate OpenAPI parsing
CVE-2026-49451 · GHSA-v5pm-xwqc-g5wc
- Affected
- NuGet microsoft.openapi >= 3.0.0, <= 3.5.3; >= 2.0.0-preview.11, <= 2.7.4
- Fixed in
- 3.5.42.7.5· Vendor fix available
- Issue
- Impact 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. Affected versions - = 2.0.0-preview.11, <= 2.7.4 - = 3.0.0, <= 3.5.3 Patches - For the 2.X major version, versions 2.7.5 and above are patched. - For the 3.X major version, versions 3.5.4 and above are patched. - For the 1.X major version, the issue does not apply since that version of the library could not resolve references that pointed to another reference. Impact Applications, CLIs, developer tools, or services that parse untrusted OpenAPI documents in-process may be terminated by a crafted OpenAPI document containing circular schema references. The impact is availability/process termination only. This report does not claim remote code execution, authentication bypass, credential exposure,…
Recommended action: Upgrade to 3.5.4 or 2.7.5 by release line, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.