diff --git a/bazel/grpc_deps.bzl b/bazel/grpc_deps.bzl
index 151825c6839..596ffb0ae50 100644
--- a/bazel/grpc_deps.bzl
+++ b/bazel/grpc_deps.bzl
@@ -178,19 +178,19 @@ def grpc_deps():
     if "com_google_absl" not in native.existing_rules():
         http_archive(
             name = "com_google_absl",
-            sha256 = "5fe2a3a8f8378e81d4d3db6541f48030e04233ccd2d6c7e9d981ed577b314ae8",
-            strip_prefix = "abseil-cpp-308ce31528a7edfa39f5f6d36142278a0ae1bf45",
-            url = "https://github.com/abseil/abseil-cpp/archive/308ce31528a7edfa39f5f6d36142278a0ae1bf45.tar.gz",
+            sha256 = "7ddf863ddced6fa5bf7304103f9c7aa619c20a2fcf84475512c8d3834b9d14fa",
+            strip_prefix = "abseil-cpp-61c9bf3e3e1c28a4aa6d7f1be4b37fd473bb5529",
+            url = "https://github.com/abseil/abseil-cpp/archive/61c9bf3e3e1c28a4aa6d7f1be4b37fd473bb5529.tar.gz",
         )
 
     if "bazel_toolchains" not in native.existing_rules():
         http_archive(
             name = "bazel_toolchains",
-            sha256 = "88e818f9f03628eef609c8429c210ecf265ffe46c2af095f36c7ef8b1855fef5",
-            strip_prefix = "bazel-toolchains-92dd8a7a518a2fb7ba992d47c8b38299fe0be825",
+            sha256 = "d968b414b32aa99c86977e1171645d31da2b52ac88060de3ac1e49932d5dcbf1",
+            strip_prefix = "bazel-toolchains-4bd5df80d77aa7f4fb943dfdfad5c9056a62fb47",
             urls = [
-                "https://mirror.bazel.build/github.com/bazelbuild/bazel-toolchains/archive/92dd8a7a518a2fb7ba992d47c8b38299fe0be825.tar.gz",
-                "https://github.com/bazelbuild/bazel-toolchains/archive/92dd8a7a518a2fb7ba992d47c8b38299fe0be825.tar.gz",
+                "https://mirror.bazel.build/github.com/bazelbuild/bazel-toolchains/archive/4bd5df80d77aa7f4fb943dfdfad5c9056a62fb47.tar.gz",
+                "https://github.com/bazelbuild/bazel-toolchains/archive/4bd5df80d77aa7f4fb943dfdfad5c9056a62fb47.tar.gz",
             ],
         )
 
@@ -205,9 +205,9 @@ def grpc_deps():
     if "io_opencensus_cpp" not in native.existing_rules():
         http_archive(
             name = "io_opencensus_cpp",
-            sha256 = "3436ca23dc1b3345186defd0f46d64244079ba3d3234a0c5d6ef5e8d5d06c8b5",
-            strip_prefix = "opencensus-cpp-9b1e354e89bf3d92aedc00af45b418ce870f3d77",
-            url = "https://github.com/census-instrumentation/opencensus-cpp/archive/9b1e354e89bf3d92aedc00af45b418ce870f3d77.tar.gz",
+            sha256 = "90d6fafa8b1a2ea613bf662731d3086e1c2ed286f458a95c81744df2dbae41b1",
+            strip_prefix = "opencensus-cpp-c9a4da319bc669a772928ffc55af4a61be1a1176",
+            url = "https://github.com/census-instrumentation/opencensus-cpp/archive/c9a4da319bc669a772928ffc55af4a61be1a1176.tar.gz",
         )
 
     if "upb" not in native.existing_rules():
diff --git a/examples/python/multiprocessing/BUILD b/examples/python/multiprocessing/BUILD
index 0e135f471f2..f9fa6598068 100644
--- a/examples/python/multiprocessing/BUILD
+++ b/examples/python/multiprocessing/BUILD
@@ -36,7 +36,7 @@ py_binary(
         "//src/python/grpcio/grpc:grpcio",
         ":prime_proto_pb2",
     ],
-    default_python_version = "PY3",
+    srcs_version = "PY3",
 )
 
 py_binary(
@@ -50,7 +50,7 @@ py_binary(
         "//conditions:default": [requirement("futures")],
         "//:python3": [],
     }),
-    default_python_version = "PY3",
+    srcs_version = "PY3",
 )
 
 py_test(
diff --git a/templates/tools/dockerfile/bazel.include b/templates/tools/dockerfile/bazel.include
index 272936007da..adde6ed4787 100644
--- a/templates/tools/dockerfile/bazel.include
+++ b/templates/tools/dockerfile/bazel.include
@@ -2,7 +2,7 @@
 # Bazel installation
 
 # Must be in sync with tools/bazel
-ENV BAZEL_VERSION 0.24.1
+ENV BAZEL_VERSION 0.26.0
 
 # The correct bazel version is already preinstalled, no need to use //tools/bazel wrapper.
 ENV DISABLE_BAZEL_WRAPPER 1
diff --git a/tools/bazel b/tools/bazel
index bacfeaddfd2..4f08d18c656 100755
--- a/tools/bazel
+++ b/tools/bazel
@@ -32,7 +32,7 @@ then
   exec -a "$0" "${BAZEL_REAL}" "$@"
 fi
 
-VERSION=0.24.1
+VERSION=0.26.0
 
 echo "INFO: Running bazel wrapper (see //tools/bazel for details), bazel version $VERSION will be used instead of system-wide bazel installation."
 
diff --git a/tools/bazel.rc b/tools/bazel.rc
index 99347495361..4bd3a5d7445 100644
--- a/tools/bazel.rc
+++ b/tools/bazel.rc
@@ -51,6 +51,10 @@ build:ubsan --copt=-DUNDEFINED_BEHAVIOR_SANITIZER  # used by absl
 build:ubsan --copt=-fno-sanitize=function,vptr
 build:ubsan --linkopt=-fsanitize=undefined
 build:ubsan --action_env=UBSAN_OPTIONS=halt_on_error=1:print_stacktrace=1:suppressions=test/core/util/ubsan_suppressions.txt
+# For some reasons, these two stopped being propagated, so, redeclaring them here.
+# That's a hack that needs to be removed once we understand what's going on.
+build:ubsan --copt=-DPB_FIELD_32BIT=1
+build:ubsan --copt=-DGRPC_PORT_ISOLATED_RUNTIME=1
 
 build:basicprof --strip=never
 build:basicprof --copt=-DNDEBUG
@@ -59,5 +63,5 @@ build:basicprof --copt=-DGRPC_BASIC_PROFILER
 build:basicprof --copt=-DGRPC_TIMERS_RDTSC
 
 build:python3 --python_path=python3
-build:python3 --force_python=PY3
+build:python3 --python_version=PY3
 build:python3 --action_env=PYTHON_BIN_PATH=python3
diff --git a/tools/dockerfile/test/bazel/Dockerfile b/tools/dockerfile/test/bazel/Dockerfile
index df7a7a2f32a..7e7903359e7 100644
--- a/tools/dockerfile/test/bazel/Dockerfile
+++ b/tools/dockerfile/test/bazel/Dockerfile
@@ -52,7 +52,7 @@ RUN pip install futures==2.2.0 enum34==1.0.4 protobuf==3.5.2.post1 six==1.10.0 t
 # Bazel installation
 
 # Must be in sync with tools/bazel
-ENV BAZEL_VERSION 0.24.1
+ENV BAZEL_VERSION 0.26.0
 
 # The correct bazel version is already preinstalled, no need to use //tools/bazel wrapper.
 ENV DISABLE_BAZEL_WRAPPER 1
diff --git a/tools/dockerfile/test/sanity/Dockerfile b/tools/dockerfile/test/sanity/Dockerfile
index 9a080d0efb2..ca786e264ed 100644
--- a/tools/dockerfile/test/sanity/Dockerfile
+++ b/tools/dockerfile/test/sanity/Dockerfile
@@ -98,7 +98,7 @@ ENV CLANG_TIDY=clang-tidy
 # Bazel installation
 
 # Must be in sync with tools/bazel
-ENV BAZEL_VERSION 0.24.1
+ENV BAZEL_VERSION 0.26.0
 
 # The correct bazel version is already preinstalled, no need to use //tools/bazel wrapper.
 ENV DISABLE_BAZEL_WRAPPER 1
diff --git a/tools/remote_build/rbe_common.bazelrc b/tools/remote_build/rbe_common.bazelrc
index 63b49c5c42d..6baaf24732c 100644
--- a/tools/remote_build/rbe_common.bazelrc
+++ b/tools/remote_build/rbe_common.bazelrc
@@ -84,4 +84,7 @@ build:ubsan --copt=-gmlt
 # TODO(jtattermusch): use more reasonable test timeout
 build:ubsan --test_timeout=3600
 # override the config-agnostic crosstool_top
+# how to update the bazel toolchain for ubsan:
+# - check for the latest released version in https://github.com/bazelbuild/bazel-toolchains/tree/master/configs/experimental/ubuntu16_04_clang
+# - you might need to update the bazel_toolchains dependency in grpc_deps.bzl
 build:ubsan --crosstool_top=@bazel_toolchains//configs/experimental/ubuntu16_04_clang/1.2/bazel_0.23.0/ubsan:toolchain