diff --git a/src/dotnet/Directory.Packages.props b/src/dotnet/Directory.Packages.props
index 9a77a5ad..f9d7b182 100644
--- a/src/dotnet/Directory.Packages.props
+++ b/src/dotnet/Directory.Packages.props
@@ -26,6 +26,12 @@
     <PackageVersion Include="ITfoxtec.Identity.Saml2.MvcCore" Version="4.18.0" />
     <PackageVersion Include="Yarp.ReverseProxy" Version="2.3.0" />
     <PackageVersion Include="Microsoft.AspNetCore.OpenApi" Version="10.0.8" />
+    <!-- Transitive-CVE pin: Microsoft.AspNetCore.OpenApi floats Microsoft.OpenApi
+         at [2.0.0, ), which resolves to the vulnerable 2.0.0
+         (GHSA-v5pm-xwqc-g5wc, circular-schema-reference DoS in parsing).
+         Referenced directly from Modgud.Api so the whole graph lifts to the
+         patched 2.x. Drop this once AspNetCore.OpenApi requires >= 2.7.5. -->
+    <PackageVersion Include="Microsoft.OpenApi" Version="2.7.5" />
     <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="10.0.8" />
     <PackageVersion Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.8" />
     <PackageVersion Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" Version="1.23.0" />
diff --git a/src/dotnet/Modgud.Api/Modgud.Api.csproj b/src/dotnet/Modgud.Api/Modgud.Api.csproj
index 6df9498d..777f10c2 100644
--- a/src/dotnet/Modgud.Api/Modgud.Api.csproj
+++ b/src/dotnet/Modgud.Api/Modgud.Api.csproj
@@ -22,6 +22,9 @@
     <PackageReference Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" />
     <PackageReference Include="Serilog.AspNetCore" />
     <PackageReference Include="Microsoft.AspNetCore.OpenApi" />
+    <!-- Direct reference solely to pin the transitive above the vulnerable
+         2.0.0 — see the note in Directory.Packages.props. -->
+    <PackageReference Include="Microsoft.OpenApi" />
     <PackageReference Include="Cocoar.JsEval.TsDefinition" />
     <PackageReference Include="Cocoar.Reflectensions" />
     <PackageReference Include="Cocoar.SignalARRR.Server" />