diff --git a/src/Servers/IIS/IIS/test/Common.FunctionalTests/Inprocess/SynchronousReadAndWriteTests.cs b/src/Servers/IIS/IIS/test/Common.FunctionalTests/Inprocess/SynchronousReadAndWriteTests.cs
index fd80665c6f..78d1857528 100644
--- a/src/Servers/IIS/IIS/test/Common.FunctionalTests/Inprocess/SynchronousReadAndWriteTests.cs
+++ b/src/Servers/IIS/IIS/test/Common.FunctionalTests/Inprocess/SynchronousReadAndWriteTests.cs
@@ -22,6 +22,7 @@ namespace Microsoft.AspNetCore.Server.IIS.FunctionalTests.InProcess
         }
 
         [ConditionalFact]
+        [QuarantinedTest("https://github.com/dotnet/aspnetcore/issues/26294")]
         public async Task ReadAndWriteSynchronously()
         {
             var content = new StringContent(new string('a', 100000));
diff --git a/src/Servers/Kestrel/test/InMemory.FunctionalTests/Http2/Http2ConnectionTests.cs b/src/Servers/Kestrel/test/InMemory.FunctionalTests/Http2/Http2ConnectionTests.cs
index 110575221c..794fdf1946 100644
--- a/src/Servers/Kestrel/test/InMemory.FunctionalTests/Http2/Http2ConnectionTests.cs
+++ b/src/Servers/Kestrel/test/InMemory.FunctionalTests/Http2/Http2ConnectionTests.cs
@@ -1503,6 +1503,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
         }
 
         [Fact]
+        [QuarantinedTest("https://github.com/dotnet/aspnetcore/issues/26291")]
         public Task Frame_MultipleStreams_RequestsNotFinished_DefaultMaxStreamsPerConnection_EnhanceYourCalmAfterDoubleMaxStreams()
         {
             // Kestrel tracks max streams per connection * 2