diff --git a/dotnet/Directory.Packages.props b/dotnet/Directory.Packages.props
index 9cae6f0a8648..2eaf16a66618 100644
--- a/dotnet/Directory.Packages.props
+++ b/dotnet/Directory.Packages.props
@@ -171,6 +171,7 @@
     <PackageVersion Include="DuckDB.NET.Data.Full" Version="1.2.0" />
     <PackageVersion Include="DuckDB.NET.Data" Version="1.1.3" />
     <PackageVersion Include="MongoDB.Driver" Version="3.5.2" />
+    <PackageVersion Include="Snappier" Version="1.3.1" /><!-- Vulnerability fix: GHSA-pggp-6c3x-2xmx; transitively pinned via MongoDB.Driver -->
     <PackageVersion Include="Microsoft.Graph" Version="5.94.0" />
     <PackageVersion Include="Microsoft.OpenApi" Version="1.6.24" />
     <PackageVersion Include="Microsoft.OpenApi.Readers" Version="1.6.24" />
diff --git a/dotnet/src/VectorData/CosmosMongoDB/CosmosMongoDB.csproj b/dotnet/src/VectorData/CosmosMongoDB/CosmosMongoDB.csproj
index 52b98d55b40e..6cfc45fc2881 100644
--- a/dotnet/src/VectorData/CosmosMongoDB/CosmosMongoDB.csproj
+++ b/dotnet/src/VectorData/CosmosMongoDB/CosmosMongoDB.csproj
@@ -30,6 +30,7 @@
 
   <ItemGroup>
     <PackageReference Include="MongoDB.Driver" />
+    <PackageReference Include="Snappier" /><!-- Pin to patched version; overrides transitive 1.0.0 from MongoDB.Driver (GHSA-pggp-6c3x-2xmx) -->
   </ItemGroup>
 
   <ItemGroup>
diff --git a/dotnet/src/VectorData/MongoDB/MongoDB.csproj b/dotnet/src/VectorData/MongoDB/MongoDB.csproj
index fa6369f2e179..d3200c604133 100644
--- a/dotnet/src/VectorData/MongoDB/MongoDB.csproj
+++ b/dotnet/src/VectorData/MongoDB/MongoDB.csproj
@@ -30,6 +30,7 @@
 
   <ItemGroup>
     <PackageReference Include="MongoDB.Driver" />
+    <PackageReference Include="Snappier" /><!-- Pin to patched version; overrides transitive 1.0.0 from MongoDB.Driver (GHSA-pggp-6c3x-2xmx) -->
   </ItemGroup>
 
   <ItemGroup>