diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
index 8deb3b7b97c9..bf20cfecb586 100644
--- a/eng/Version.Details.xml
+++ b/eng/Version.Details.xml
@@ -26,13 +26,13 @@
       <Uri>https://github.com/dotnet/core-setup</Uri>
       <Sha>d2d36e7b1e0081effa2bb220fb88238392fdc389</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.NETCore.Platforms" Version="3.0.0-preview6.19265.6">
+    <Dependency Name="Microsoft.NETCore.Platforms" Version="3.0.0-preview6.19266.12">
       <Uri>https://github.com/dotnet/corefx</Uri>
-      <Sha>fb97a8b5043dc4f92e437e3b21fb33e7493f1b3a</Sha>
+      <Sha>6f9570e012054bf407778c0b07632e7733ecbb13</Sha>
     </Dependency>
-    <Dependency Name="runtime.native.System.IO.Ports" Version="4.6.0-preview6.19265.6">
+    <Dependency Name="runtime.native.System.IO.Ports" Version="4.6.0-preview6.19266.12">
       <Uri>https://github.com/dotnet/corefx</Uri>
-      <Sha>fb97a8b5043dc4f92e437e3b21fb33e7493f1b3a</Sha>
+      <Sha>6f9570e012054bf407778c0b07632e7733ecbb13</Sha>
     </Dependency>
     <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="1.0.0-beta.19264.13">
       <Uri>https://github.com/dotnet/arcade</Uri>
diff --git a/eng/Versions.props b/eng/Versions.props
index f7d908cf84f0..4c253f491ee6 100644
--- a/eng/Versions.props
+++ b/eng/Versions.props
@@ -43,8 +43,8 @@
     <MicrosoftNETCoreILAsmPackageVersion>3.0.0-preview6-27714-72</MicrosoftNETCoreILAsmPackageVersion>
     <MicrosoftNETCoreRuntimeCoreCLRPackageVersion>3.0.0-preview6-27714-72</MicrosoftNETCoreRuntimeCoreCLRPackageVersion>
     <!-- Corefx dependencies -->
-    <MicrosoftNETCorePlatformsPackageVersion>3.0.0-preview6.19265.6</MicrosoftNETCorePlatformsPackageVersion>
-    <runtimenativeSystemIOPortsPackageVersion>4.6.0-preview6.19265.6</runtimenativeSystemIOPortsPackageVersion>
+    <MicrosoftNETCorePlatformsPackageVersion>3.0.0-preview6.19266.12</MicrosoftNETCorePlatformsPackageVersion>
+    <runtimenativeSystemIOPortsPackageVersion>4.6.0-preview6.19266.12</runtimenativeSystemIOPortsPackageVersion>
     <!-- Standard dependencies -->
     <NETStandardLibraryPackageVersion>2.1.0-prerelease.19265.2</NETStandardLibraryPackageVersion>
     <!-- dotnet-optimization dependencies -->