diff --git a/conformance/BUILD b/conformance/BUILD
index e3c22bb0fb1f4..b6bbbc4cdeec9 100644
--- a/conformance/BUILD
+++ b/conformance/BUILD
@@ -143,7 +143,6 @@ cc_library(
         "//editions:test_messages_proto2_editions_cc_proto",
         "//editions:test_messages_proto3_editions_cc_proto",
         "//src/google/protobuf",
-        "//src/google/protobuf:endian",
         "//src/google/protobuf:protobuf_lite",
         "//src/google/protobuf/json",
         "//src/google/protobuf/util:type_resolver",
diff --git a/conformance/binary_json_conformance_suite.cc b/conformance/binary_json_conformance_suite.cc
index 62c9294893a09..46a1517d5f0a7 100644
--- a/conformance/binary_json_conformance_suite.cc
+++ b/conformance/binary_json_conformance_suite.cc
@@ -3471,6 +3471,68 @@ void BinaryAndJsonConformanceSuiteImpl<MessageType>::RunJsonTestsForStruct() {
     }
   }
       )");
+
+  std::string deep_json = R"({"optionalStruct": {)";
+  std::string deep_proto = "optional_struct: {\n";
+  int depth = 25;
+  for (int i = 0; i < depth; ++i) {
+    deep_json += R"("n": {)";
+    deep_proto += R"(  fields: {
+    key: "n"
+    value: {
+      struct_value: {
+)";
+  }
+  deep_json += R"("value": 1)";
+  deep_proto += R"(        fields: {
+          key: "value"
+          value: {
+            number_value: 1
+          }
+        }
+)";
+
+  for (int i = 0; i < depth; ++i) {
+    deep_json += '}';
+    deep_proto += R"(      }
+    }
+  }
+)";
+  }
+  deep_json += "}}";
+  deep_proto += "}\n";
+
+  RunValidJsonTest("StructDeepNesting25", REQUIRED, deep_json, deep_proto);
+
+  {
+    std::string deep_json = R"({"optionalStruct": {)";
+    int depth = 90;
+    for (int i = 0; i < depth; ++i) {
+      deep_json += R"("n": {)";
+    }
+    deep_json += R"("value": 1)";
+    for (int i = 0; i < depth; ++i) {
+      deep_json += '}';
+    }
+    deep_json += "}}";
+
+    ExpectParseFailureForJson("StructDeepNesting90", REQUIRED, deep_json);
+  }
+
+  {
+    std::string deep_json = R"({"optionalStruct": {)";
+    int depth = 200;
+    for (int i = 0; i < depth; ++i) {
+      deep_json += R"("n": {)";
+    }
+    deep_json += R"("value": 1)";
+    for (int i = 0; i < depth; ++i) {
+      deep_json += '}';
+    }
+    deep_json += "}}";
+
+    ExpectParseFailureForJson("StructDeepNesting200", REQUIRED, deep_json);
+  }
 }
 
 template <typename MessageType>
@@ -3561,6 +3623,54 @@ void BinaryAndJsonConformanceSuiteImpl<MessageType>::RunJsonTestsForValue() {
                                 "optional_value: { number_value: nan}");
   ExpectSerializeFailureForJson("ValueRejectInfNumberValue", RECOMMENDED,
                                 "optional_value: { number_value: inf}");
+
+  {
+    std::string deep_json = R"({"optionalValue": )";
+    std::string deep_proto = "optional_value: {\n";
+    int depth = 25;
+    for (int i = 0; i < depth; ++i) {
+      deep_json += '[';
+      deep_proto += "  list_value: {\n    values: {\n";
+    }
+    deep_json += '1';
+    deep_proto += "      number_value: 1\n";
+    for (int i = 0; i < depth; ++i) {
+      deep_json += ']';
+      deep_proto += "    }\n  }\n";
+    }
+    deep_json += '}';
+    deep_proto += "}\n";
+
+    RunValidJsonTest("ValueDeepNesting", REQUIRED, deep_json, deep_proto);
+  }
+  {
+    std::string deep_json = R"({"optionalValue": )";
+    int depth = 90;
+    for (int i = 0; i < depth; ++i) {
+      deep_json += '[';
+    }
+    deep_json += '1';
+    for (int i = 0; i < depth; ++i) {
+      deep_json += ']';
+    }
+    deep_json += '}';
+
+    ExpectParseFailureForJson("ValueDeepNesting90", REQUIRED, deep_json);
+  }
+  {
+    std::string deep_json = R"({"optionalValue": )";
+    int depth = 200;
+    for (int i = 0; i < depth; ++i) {
+      deep_json += '[';
+    }
+    deep_json += '1';
+    for (int i = 0; i < depth; ++i) {
+      deep_json += ']';
+    }
+    deep_json += '}';
+
+    ExpectParseFailureForJson("ValueDeepNesting200", REQUIRED, deep_json);
+  }
 }
 
 template <typename MessageType>
diff --git a/conformance/failure_list_cpp.txt b/conformance/failure_list_cpp.txt
index f2d114909c9f4..7089833ba2b78 100644
--- a/conformance/failure_list_cpp.txt
+++ b/conformance/failure_list_cpp.txt
@@ -34,6 +34,7 @@ Recommended.*.FieldMaskTooManyUnderscore.JsonOutput
 Recommended.*.JsonInput.FieldMaskInvalidCharacter                                                                  # Should have failed to parse, but didn't.
 Required.*.JsonInput.SingleValueForRepeatedFieldInt32                                                              # Should have failed to parse, but didn't.
 Required.*.JsonInput.SingleValueForRepeatedFieldMessage                                                            # Should have failed to parse, but didn't.
+Required.*.JsonInput.StructDeepNesting90                                                                           # Should have failed to parse, but didn't.
 Required.*.ProtobufInput.BadTag_FieldNumberSlightlyTooHigh                                                         # Should have failed to parse, but didn't.
 # TODO: Uncomment once conformance tests can express failures that are not expected to be fixed.
 # Recommended.Editions_Proto2.ProtobufInput.RejectInvalidUtf8.String.MapKey                                          # Should have failed to parse, but didn't.
diff --git a/conformance/failure_list_java.txt b/conformance/failure_list_java.txt
index 94c9871484a68..cc076a1f7105d 100644
--- a/conformance/failure_list_java.txt
+++ b/conformance/failure_list_java.txt
@@ -42,6 +42,8 @@ Required.*.JsonInput.Int32FieldPlusSign
 Required.*.JsonInput.RepeatedFieldWrongElementTypeExpectingStringsGotBool                                          # Should have failed to parse, but didn't.
 Required.*.JsonInput.RepeatedFieldWrongElementTypeExpectingStringsGotInt                                           # Should have failed to parse, but didn't.
 Required.*.JsonInput.StringFieldNotAString                                                                         # Should have failed to parse, but didn't.
+Required.*.JsonInput.StructDeepNesting90                                                                           # Should have failed to parse, but didn't.
+Required.*.JsonInput.ValueDeepNesting90                                                                            # Should have failed to parse, but didn't.
 Required.*.ProtobufInput.UnknownOrdering.ProtobufOutput                                                            # Unknown field mismatch
 Required.*.ProtobufInput.BadTag_FieldNumberTooHigh                                                                 # Should have failed to parse, but didn't.
 Required.*.ProtobufInput.BadTag_FieldNumberSlightlyTooHigh                                                         # Should have failed to parse, but didn't.
diff --git a/conformance/failure_list_python.txt b/conformance/failure_list_python.txt
index bd8e7703ba508..0f35dbed0bf0a 100644
--- a/conformance/failure_list_python.txt
+++ b/conformance/failure_list_python.txt
@@ -1,5 +1,6 @@
-Recommended.*.JsonInput.FieldNameDuplicateDifferentCasing1 # Should have failed to parse, but didn't.
-Recommended.*.JsonInput.FieldNameDuplicateDifferentCasing2 # Should have failed to parse, but didn't.
+Recommended.*.JsonInput.FieldNameDuplicateDifferentCasing1                                                         # Should have failed to parse, but didn't.
+Recommended.*.JsonInput.FieldNameDuplicateDifferentCasing2                                                         # Should have failed to parse, but didn't.
+Required.*.JsonInput.StructDeepNesting25.ProtobufOutput                                                              # Failed to parse input or produce output.
 Required.*.ProtobufInput.BadTag_FieldNumberTooHigh                                                                 # Should have failed to parse, but didn't.
 Required.*.ProtobufInput.BadTag_FieldNumberSlightlyTooHigh                                                         # Should have failed to parse, but didn't.
 Required.*.ProtobufInput.BadTag_OverlongVarint                                                                     # Should have failed to parse, but didn't.