diff --git a/NuGet.config b/NuGet.config
index d74fa2a4c62854..978d89e38470ee 100644
--- a/NuGet.config
+++ b/NuGet.config
@@ -9,7 +9,7 @@
     <clear />
     <!--Begin: Package sources managed by Dependency Flow automation. Do not edit the sources below.-->
     <!--  Begin: Package sources from dotnet-emsdk -->
-    <add key="darc-pub-dotnet-emsdk-badf9f9" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/darc-pub-dotnet-emsdk-badf9f97/nuget/v3/index.json" />
+    <add key="darc-pub-dotnet-emsdk-050048d" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/darc-pub-dotnet-emsdk-050048d7/nuget/v3/index.json" />
     <!--  End: Package sources from dotnet-emsdk -->
     <!--  Begin: Package sources from dotnet-sdk -->
     <!--  End: Package sources from dotnet-sdk -->
diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
index 940882698680c7..94f32a178ae9f4 100644
--- a/eng/Version.Details.xml
+++ b/eng/Version.Details.xml
@@ -90,13 +90,13 @@
       <Sha>8bb0f2d5f3b6b9dff32e2643642bea09bf6ae38d</Sha>
       <SourceBuild RepoName="cecil" ManagedOnly="true" />
     </Dependency>
-    <Dependency Name="Microsoft.NET.Workload.Emscripten.Current.Manifest-8.0.100" Version="8.0.25">
+    <Dependency Name="Microsoft.NET.Workload.Emscripten.Current.Manifest-8.0.100" Version="8.0.26">
       <Uri>https://github.com/dotnet/emsdk</Uri>
-      <Sha>badf9f97aaf4c2166b17bd6475ca73958c11e309</Sha>
+      <Sha>050048d77141e904449880ff47a38da3a7f515b6</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.SourceBuild.Intermediate.emsdk" Version="8.0.25-servicing.26102.2">
+    <Dependency Name="Microsoft.SourceBuild.Intermediate.emsdk" Version="8.0.26-servicing.26160.3">
       <Uri>https://github.com/dotnet/emsdk</Uri>
-      <Sha>badf9f97aaf4c2166b17bd6475ca73958c11e309</Sha>
+      <Sha>050048d77141e904449880ff47a38da3a7f515b6</Sha>
       <SourceBuild RepoName="emsdk" ManagedOnly="true" />
     </Dependency>
     <Dependency Name="Microsoft.SourceBuild.Intermediate.source-build-reference-packages" Version="8.0.0-alpha.1.25615.3">
diff --git a/eng/Versions.props b/eng/Versions.props
index a3b591f1997833..e1332f2c5f1fdf 100644
--- a/eng/Versions.props
+++ b/eng/Versions.props
@@ -1,11 +1,11 @@
 <Project>
   <PropertyGroup>
     <!-- The .NET product branding version -->
-    <ProductVersion>8.0.25</ProductVersion>
+    <ProductVersion>8.0.26</ProductVersion>
     <!-- File version numbers -->
     <MajorVersion>8</MajorVersion>
     <MinorVersion>0</MinorVersion>
-    <PatchVersion>25</PatchVersion>
+    <PatchVersion>26</PatchVersion>
     <SdkBandVersion>8.0.100</SdkBandVersion>
     <PackageVersionNet7>7.0.20</PackageVersionNet7>
     <PackageVersionNet6>6.0.36</PackageVersionNet6>
@@ -253,7 +253,7 @@
          Note: when the name is updated, make sure to update dependency name in eng/pipelines/common/xplat-setup.yml
                like - DarcDependenciesChanged.Microsoft_NET_Workload_Emscripten_Current_Manifest-8_0_100_Transport
     -->
-    <MicrosoftNETWorkloadEmscriptenCurrentManifest80100Version>8.0.25</MicrosoftNETWorkloadEmscriptenCurrentManifest80100Version>
+    <MicrosoftNETWorkloadEmscriptenCurrentManifest80100Version>8.0.26</MicrosoftNETWorkloadEmscriptenCurrentManifest80100Version>
     <MicrosoftNETRuntimeEmscriptenVersion>$(MicrosoftNETWorkloadEmscriptenCurrentManifest80100Version)</MicrosoftNETRuntimeEmscriptenVersion>
     <!-- SdkVersionForWorkloadTesting is used to compute the sdk band and version for workload testing.
          The published manifests are built in dotnet/sdk so these values are for testing purposes only.
diff --git a/src/libraries/System.IO.FileSystem/tests/Base/SymbolicLinks/BaseSymbolicLinks.cs b/src/libraries/System.IO.FileSystem/tests/Base/SymbolicLinks/BaseSymbolicLinks.cs
index adaec2b9094f00..f08d4a0ce2dcc2 100644
--- a/src/libraries/System.IO.FileSystem/tests/Base/SymbolicLinks/BaseSymbolicLinks.cs
+++ b/src/libraries/System.IO.FileSystem/tests/Base/SymbolicLinks/BaseSymbolicLinks.cs
@@ -57,11 +57,18 @@ public static IEnumerable<object[]> SymbolicLink_ResolveLinkTarget_PathToTarget_
         {
             get
             {
-                foreach (string path in PathToTargetData.Union(PathToTargetUncData))
+                foreach (string path in PathToTargetData)
                 {
                     yield return new object[] { path, false };
                     yield return new object[] { path, true };
                 }
+                // UNC paths are excluded from the returnFinalTarget=true case since
+                // they throw "The specified network name is no longer available" in
+                // various Windows versions. https://github.com/dotnet/runtime/issues/120380
+                foreach (string path in PathToTargetUncData)
+                {
+                    yield return new object[] { path, false };
+                }
             }
         }
 
diff --git a/src/libraries/System.Net.WebSockets/src/Resources/Strings.resx b/src/libraries/System.Net.WebSockets/src/Resources/Strings.resx
index 8e01fce49ad888..fdf7ea01987c61 100644
--- a/src/libraries/System.Net.WebSockets/src/Resources/Strings.resx
+++ b/src/libraries/System.Net.WebSockets/src/Resources/Strings.resx
@@ -117,6 +117,9 @@
   <data name="net_Websockets_ClientReceivedMaskedFrame" xml:space="preserve">
     <value>The WebSocket server sent a masked frame.</value>
   </data>
+  <data name="net_Websockets_ServerReceivedUnmaskedFrame" xml:space="preserve">
+    <value>The WebSocket client sent an unmasked frame.</value>
+  </data>
   <data name="net_Websockets_ContinuationFromFinalFrame" xml:space="preserve">
     <value>The WebSocket received a continuation frame from a previous final message.</value>
   </data>
diff --git a/src/libraries/System.Net.WebSockets/src/System/Net/WebSockets/ManagedWebSocket.cs b/src/libraries/System.Net.WebSockets/src/System/Net/WebSockets/ManagedWebSocket.cs
index bcf6500a8a6306..ff4c7935aa2dc2 100644
--- a/src/libraries/System.Net.WebSockets/src/System/Net/WebSockets/ManagedWebSocket.cs
+++ b/src/libraries/System.Net.WebSockets/src/System/Net/WebSockets/ManagedWebSocket.cs
@@ -1204,6 +1204,11 @@ private async ValueTask CloseWithReceiveErrorAndThrowAsync(
                 // Consume the mask bytes
                 ConsumeFromBuffer(4);
             }
+            else if (_isServer)
+            {
+                resultHeader = default;
+                return SR.net_Websockets_ServerReceivedUnmaskedFrame;
+            }
 
             // Do basic validation of the header
             switch (header.Opcode)
diff --git a/src/libraries/System.Net.WebSockets/tests/WebSocketTests.cs b/src/libraries/System.Net.WebSockets/tests/WebSocketTests.cs
index 3d0b54bd8ea5b5..fd852f03710924 100644
--- a/src/libraries/System.Net.WebSockets/tests/WebSocketTests.cs
+++ b/src/libraries/System.Net.WebSockets/tests/WebSocketTests.cs
@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 using Xunit;
 
@@ -184,6 +185,20 @@ public async Task ThrowWhenContinuationWithDifferentCompressionFlags()
                client.SendAsync(Memory<byte>.Empty, WebSocketMessageType.Binary, WebSocketMessageFlags.EndOfMessage, default));
         }
 
+        [Fact]
+        public async Task ReceiveAsync_ServerUnmaskedFrame_ThrowsWebSocketException()
+        {
+            byte[] frame = { 0x81, 0x05, 0x48, 0x65, 0x6C, 0x6C, 0x6F };
+            using var stream = new MemoryStream();
+            stream.Write(frame, 0, frame.Length);
+            stream.Position = 0;
+            using WebSocket websocket = WebSocket.CreateFromStream(stream, new WebSocketCreationOptions { IsServer = true });
+            WebSocketException exception = await Assert.ThrowsAsync<WebSocketException>(() =>
+                websocket.ReceiveAsync(new byte[5], CancellationToken.None));
+            Assert.Equal("The WebSocket client sent an unmasked frame.", exception.Message);
+            Assert.Equal(WebSocketState.Aborted, websocket.State);
+        }
+
         public abstract class ExposeProtectedWebSocket : WebSocket
         {
             public static new bool IsStateTerminal(WebSocketState state) =>
diff --git a/src/libraries/System.Security.Cryptography.Cose/src/System.Security.Cryptography.Cose.csproj b/src/libraries/System.Security.Cryptography.Cose/src/System.Security.Cryptography.Cose.csproj
index 1b411e3ce4f158..71b7a09b0286b3 100644
--- a/src/libraries/System.Security.Cryptography.Cose/src/System.Security.Cryptography.Cose.csproj
+++ b/src/libraries/System.Security.Cryptography.Cose/src/System.Security.Cryptography.Cose.csproj
@@ -5,7 +5,7 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IsPackable>true</IsPackable>
     <ServicingVersion>2</ServicingVersion>
-    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <GeneratePackageOnBuild>false</GeneratePackageOnBuild>
     <PackageDescription>Provides support for CBOR Object Signing and Encryption (COSE).</PackageDescription>
   </PropertyGroup>