  # Install dependencies
  RUN apt-get update && apt-get -y dist-upgrade && apt-get install -y \
 diff --git a/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/Dockerfile b/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/Dockerfile
-index 65f67d36502..33a2e54bc1e 100644
+index 65f67d3650..26223753ed 100644
 --- a/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/Dockerfile
 +++ b/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/Dockerfile
 @@ -82,11 +82,10 @@ RUN pip install futures==2.2.0 enum34==1.0.4 protobuf==3.0.0a2

-RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
-RUN echo "deb http://download.mono-project.com/repo/debian wheezy main" | tee /etc/apt/sources.list.d/mono-xamarin.list
+RUN apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
+RUN echo "deb http://download.mono-project.com/repo/debian jessie main" | tee /etc/apt/sources.list.d/mono-official.list
 RUN echo "deb http://download.mono-project.com/repo/debian wheezy-apache24-compat main" | tee -a /etc/apt/sources.list.d/mono-xamarin.list
 RUN echo "deb http://download.mono-project.com/repo/debian wheezy-libjpeg62-compat main" | tee -a /etc/apt/sources.list.d/mono-xamarin.list
-RUN echo "deb http://download.mono-project.com/repo/debian wheezy-libtiff-compat main" | tee -a /etc/apt/sources.list.d/mono-xamarin.list

diff --git a/third_party/boringssl b/third_party/boringssl
index c880e42ba1..70ef9596bb 160000
--- a/third_party/boringssl
+++ b/third_party/boringssl
@@ -1 +1 @@
-Subproject commit c880e42ba1c8032d4cdde2aba0541d8a9d9fa2e9
+Subproject commit 70ef9596bbcc11353b9bb8d4e91478694dd21439
diff --git a/third_party/gflags b/third_party/gflags
index 05b155ff59..30dbc81fb5 160000
--- a/third_party/gflags
+++ b/third_party/gflags
@@ -1 +1 @@
-Subproject commit 05b155ff59114735ec8cd089f669c4c3d8f59029
+Subproject commit 30dbc81fb5ffdc98ea9b14b1918bfe4e8779b26e
diff --git a/third_party/googletest b/third_party/googletest
index c99458533a..ec44c6c167 160000
--- a/third_party/googletest
+++ b/third_party/googletest
@@ -1 +1 @@
-Subproject commit c99458533a9b4c743ed51537e25989ea55944908
+Subproject commit ec44c6c1675c25b9827aacd08c02433cccde7780
diff --git a/third_party/protobuf b/third_party/protobuf
index 1a58673508..b5fbb742af 160000
--- a/third_party/protobuf
+++ b/third_party/protobuf
@@ -1 +1 @@
-Subproject commit 1a586735085e817b1f52e53feec92ce418049f69
+Subproject commit b5fbb742af122b565925987e65c08957739976a7
diff --git a/third_party/zlib b/third_party/zlib
index 5089329162..cacf7f1d4e 160000
--- a/third_party/zlib
+++ b/third_party/zlib
@@ -1 +1 @@
-Subproject commit 50893291621658f355bc5b4d450a8d06a563053d
+Subproject commit cacf7f1d4e3d44d871b605da3b647f07d718623f
diff --git a/tools/dockerfile/interoptest/grpc_interop_csharp/Dockerfile b/tools/dockerfile/interoptest/grpc_interop_csharp/Dockerfile
index da1d2c645e..f405994293 100644
--- a/tools/dockerfile/interoptest/grpc_interop_csharp/Dockerfile
+++ b/tools/dockerfile/interoptest/grpc_interop_csharp/Dockerfile
@@ -67,11 +67,10 @@ RUN apt-get update && apt-get install -y time && apt-get clean
