diff --git a/bazel/grpc_deps.bzl b/bazel/grpc_deps.bzl
index 553c46b41cd..68c01837ffc 100644
--- a/bazel/grpc_deps.bzl
+++ b/bazel/grpc_deps.bzl
@@ -232,9 +232,9 @@ def grpc_deps():
     if "upb" not in native.existing_rules():
         http_archive(
             name = "upb",
-            sha256 = "e9f281c56ab1eb1f97a80ca8a83bb7ef73d230eabb8591f83876f4e7b85d9b47",
-            strip_prefix = "upb-8a3ae1ef3e3e3f26b45dec735c5776737fc7247f",
-            url = "https://github.com/protocolbuffers/upb/archive/8a3ae1ef3e3e3f26b45dec735c5776737fc7247f.tar.gz",
+            sha256 = "e9c136e56b98c8eb48ad1c9f8df4a6348e99f9f336ee6199c4259a312c2e3598",
+            strip_prefix = "upb-d8f3d6f9d415b31f3ce56d46791706c38fa311bc",
+            url = "https://github.com/protocolbuffers/upb/archive/d8f3d6f9d415b31f3ce56d46791706c38fa311bc.tar.gz",
         )
     if "envoy_api" not in native.existing_rules():
         http_archive(
diff --git a/third_party/upb/BUILD b/third_party/upb/BUILD
index 040d97c79c9..fa2ad904f4b 100644
--- a/third_party/upb/BUILD
+++ b/third_party/upb/BUILD
@@ -54,6 +54,17 @@ config_setting(
 
 # Public C/C++ libraries #######################################################
 
+cc_library(
+    name = "port",
+    textual_hdrs = [
+        "upb/port_def.inc",
+        "upb/port_undef.inc",
+    ],
+    srcs = [
+        "upb/port.c",
+    ],
+)
+
 cc_library(
     name = "upb",
     srcs = [
@@ -62,9 +73,6 @@ cc_library(
         "upb/generated_util.h",
         "upb/msg.c",
         "upb/msg.h",
-        "upb/port.c",
-        "upb/port_def.inc",
-        "upb/port_undef.inc",
         "upb/table.c",
         "upb/table.int.h",
         "upb/upb.c",
@@ -79,6 +87,7 @@ cc_library(
         "//conditions:default": COPTS,
     }),
     visibility = ["//visibility:public"],
+    deps = [":port"],
 )
 
 # Common support routines used by generated code.  This library has no
@@ -92,17 +101,17 @@ cc_library(
     hdrs = [
         "upb/generated_util.h",
         "upb/msg.h",
+        "upb/port_def.inc",
+        "upb/port_undef.inc",
     ],
     copts = select({
         ":windows": [],
         "//conditions:default": COPTS,
     }),
-    textual_hdrs = [
-        "upb/port_def.inc",
-        "upb/port_undef.inc",
-    ],
     visibility = ["//visibility:public"],
-    deps = [":upb"],
+    deps = [
+        ":upb",
+    ],
 )
 
 upb_proto_library(
@@ -128,6 +137,7 @@ cc_library(
     visibility = ["//visibility:public"],
     deps = [
         ":descriptor_upbproto",
+        ":port",
         ":table",
         ":upb",
     ],
@@ -138,7 +148,10 @@ cc_library(
 cc_library(
     name = "table",
     hdrs = ["upb/table.int.h"],
-    deps = [":upb"],
+    deps = [
+        ":port",
+        ":upb",
+    ],
 )
 
 # Legacy C/C++ Libraries (not recommended for new code) ########################
@@ -146,6 +159,7 @@ cc_library(
 cc_library(
     name = "legacy_msg_reflection",
     srcs = [
+        "upb/msg.h",
         "upb/legacy_msg_reflection.c",
     ],
     hdrs = ["upb/legacy_msg_reflection.h"],
@@ -154,6 +168,7 @@ cc_library(
         "//conditions:default": COPTS,
     }),
     deps = [
+        ":port",
         ":table",
         ":upb",
     ],
@@ -176,6 +191,7 @@ cc_library(
     }),
     deps = [
         ":reflection",
+        ":port",
         ":table",
         ":upb",
     ],
@@ -205,6 +221,7 @@ cc_library(
         ":descriptor_upbproto",
         ":handlers",
         ":reflection",
+        ":port",
         ":table",
         ":upb",
     ],
@@ -240,6 +257,7 @@ cc_library(
     deps = [
         ":descriptor_upbproto",
         ":handlers",
+        ":port",
         ":upb",
     ],
 )
@@ -259,9 +277,9 @@ cc_library(
         "//conditions:default": CPPOPTS,
     }),
     deps = [
-        "@absl//absl/base:core_headers",
-        "@absl//absl/container:flat_hash_map",
-        "@absl//absl/strings",
+        "@com_google_absl//absl/base:core_headers",
+        "@com_google_absl//absl/container:flat_hash_map",
+        "@com_google_absl//absl/strings",
         "@com_google_protobuf//:protobuf",
         "@com_google_protobuf//:protoc_lib",
     ],
@@ -286,6 +304,11 @@ cc_binary(
 
 # C/C++ tests ##################################################################
 
+upb_proto_reflection_library(
+    name = "descriptor_upbreflection",
+    deps = ["@com_google_protobuf//:descriptor_proto"],
+)
+
 cc_binary(
     name = "benchmark",
     testonly = 1,
@@ -313,6 +336,7 @@ cc_library(
     }),
     deps = [
         ":handlers",
+        ":port",
         ":upb",
     ],
 )
@@ -328,6 +352,7 @@ cc_test(
         "//conditions:default": COPTS,
     }),
     deps = [
+        ":port",
         ":upb",
         ":upb_pb",
         ":upb_test",
@@ -358,6 +383,7 @@ cc_test(
     }),
     deps = [
         ":handlers",
+        ":port",
         ":test_decoder_upbproto",
         ":upb",
         ":upb_pb",
@@ -386,6 +412,7 @@ cc_test(
     }),
     deps = [
         ":handlers",
+        ":port",
         ":reflection",
         ":test_cpp_upbproto",
         ":upb",
@@ -402,6 +429,7 @@ cc_test(
         "//conditions:default": CPPOPTS,
     }),
     deps = [
+        ":port",
         ":table",
         ":upb",
         ":upb_test",
@@ -431,11 +459,6 @@ cc_binary(
 )
 
 # copybara:strip_for_google3_begin
-upb_proto_reflection_library(
-    name = "descriptor_upbreflection",
-    deps = ["@com_google_protobuf//:descriptor_proto"],
-)
-
 cc_test(
     name = "test_encoder",
     srcs = ["tests/pb/test_encoder.cc"],
@@ -563,6 +586,7 @@ upb_amalgamation(
         ":descriptor_upbproto",
         ":reflection",
         ":handlers",
+        ":port",
         ":upb_pb",
         ":upb_json",
     ],
diff --git a/third_party/upb/CMakeLists.txt b/third_party/upb/CMakeLists.txt
index 836c5ff1fe5..96b265dd3a7 100644
--- a/third_party/upb/CMakeLists.txt
+++ b/third_party/upb/CMakeLists.txt
@@ -60,21 +60,22 @@ endif()
 
 enable_testing()
 
+add_library(port
+  upb/port.c)
 add_library(upb
   upb/decode.c
   upb/encode.c
   upb/generated_util.h
   upb/msg.c
   upb/msg.h
-  upb/port.c
-  upb/port_def.inc
-  upb/port_undef.inc
   upb/table.c
   upb/table.int.h
   upb/upb.c
   upb/decode.h
   upb/encode.h
   upb/upb.h)
+target_link_libraries(upb
+  port)
 add_library(generated_code_support__only_for_generated_code_do_not_use__i_give_permission_to_break_me INTERFACE)
 target_link_libraries(generated_code_support__only_for_generated_code_do_not_use__i_give_permission_to_break_me INTERFACE
   upb)
@@ -85,15 +86,19 @@ add_library(reflection
   upb/msgfactory.h)
 target_link_libraries(reflection
   descriptor_upbproto
+  port
   table
   upb)
 add_library(table INTERFACE)
 target_link_libraries(table INTERFACE
+  port
   upb)
 add_library(legacy_msg_reflection
+  upb/msg.h
   upb/legacy_msg_reflection.c
   upb/legacy_msg_reflection.h)
 target_link_libraries(legacy_msg_reflection
+  port
   table
   upb)
 add_library(handlers
@@ -104,6 +109,7 @@ add_library(handlers
   upb/sink.h)
 target_link_libraries(handlers
   reflection
+  port
   table
   upb)
 add_library(upb_pb
@@ -121,6 +127,7 @@ target_link_libraries(upb_pb
   descriptor_upbproto
   handlers
   reflection
+  port
   table
   upb)
 add_library(upb_json
@@ -135,6 +142,7 @@ add_library(upb_cc_bindings INTERFACE)
 target_link_libraries(upb_cc_bindings INTERFACE
   descriptor_upbproto
   handlers
+  port
   upb)
 add_library(upb_test
   tests/testmain.cc
@@ -142,6 +150,7 @@ add_library(upb_test
   tests/upb_test.h)
 target_link_libraries(upb_test
   handlers
+  port
   upb)
 
 
diff --git a/third_party/upb/bazel/upb_proto_library.bzl b/third_party/upb/bazel/upb_proto_library.bzl
index b30ce5d9976..bea611776c4 100644
--- a/third_party/upb/bazel/upb_proto_library.bzl
+++ b/third_party/upb/bazel/upb_proto_library.bzl
@@ -279,6 +279,7 @@ _upb_proto_reflection_library_aspect = aspect(
         ),
         "_upb": attr.label_list(
             default = [
+                "//:generated_code_support__only_for_generated_code_do_not_use__i_give_permission_to_break_me",
                 "//:upb",
                 "//:reflection",
             ],
diff --git a/third_party/upb/bazel/workspace_deps.bzl b/third_party/upb/bazel/workspace_deps.bzl
index 284277926fd..4aec3ebbd81 100644
--- a/third_party/upb/bazel/workspace_deps.bzl
+++ b/third_party/upb/bazel/workspace_deps.bzl
@@ -8,7 +8,7 @@ def upb_deps():
     )
 
     git_repository(
-        name = "absl",
+        name = "com_google_absl",
         commit = "070f6e47b33a2909d039e620c873204f78809492",
         remote = "https://github.com/abseil/abseil-cpp.git",
         shallow_since = "1541627663 -0500",
diff --git a/third_party/upb/upb/decode.c b/third_party/upb/upb/decode.c
index 4f079885950..4672b1b84ba 100644
--- a/third_party/upb/upb/decode.c
+++ b/third_party/upb/upb/decode.c
@@ -249,6 +249,10 @@ static upb_msg *upb_addmsg(upb_decframe *frame,
   upb_msg *submsg;
   upb_array *arr = upb_getorcreatearr(frame, field);
 
+  UPB_ASSERT(field->label == UPB_LABEL_REPEATED);
+  UPB_ASSERT(field->descriptortype == UPB_DESCRIPTOR_TYPE_MESSAGE ||
+             field->descriptortype == UPB_DESCRIPTOR_TYPE_GROUP);
+
   *subm = frame->layout->submsgs[field->submsg_index];
   submsg = upb_msg_new(*subm, frame->state->arena);
   CHK(submsg);
diff --git a/third_party/upb/upb/port.c b/third_party/upb/upb/port.c
index 023f7dc0ce1..9ecf135167a 100644
--- a/third_party/upb/upb/port.c
+++ b/third_party/upb/upb/port.c
@@ -1,5 +1,4 @@
 
-#include "upb/upb.h"
 #include "upb/port_def.inc"
 
 #ifdef UPB_MSVC_VSNPRINTF
diff --git a/third_party/upb/upb/port_def.inc b/third_party/upb/upb/port_def.inc
index a8967b36794..b416eaeaf1a 100644
--- a/third_party/upb/upb/port_def.inc
+++ b/third_party/upb/upb/port_def.inc
@@ -20,9 +20,7 @@
 *
 * This file is private and must not be included by users!
 */
-#ifndef UINTPTR_MAX
-#error must include stdint.h first
-#endif
+#include <stdint.h>
 
 #if UINTPTR_MAX == 0xffffffff
 #define UPB_SIZE(size32, size64) size32
diff --git a/third_party/upb/upb/table.c b/third_party/upb/upb/table.c
index 8896d217db6..fd5bc53f962 100644
--- a/third_party/upb/upb/table.c
+++ b/third_party/upb/upb/table.c
@@ -756,7 +756,8 @@ uint32_t upb_murmur_hash2(const void *key, size_t len, uint32_t seed) {
   /* Mix 4 bytes at a time into the hash */
   const uint8_t * data = (const uint8_t *)key;
   while(len >= 4) {
-    uint32_t k = *(uint32_t *)data;
+    uint32_t k;
+    memcpy(&k, data, sizeof(k));
 
     k *= m;
     k ^= k >> r;