diff --git a/php/ext/google/protobuf/php-upb.c b/php/ext/google/protobuf/php-upb.c
index fd2f3e29d4..ef9572417e 100644
--- a/php/ext/google/protobuf/php-upb.c
+++ b/php/ext/google/protobuf/php-upb.c
@@ -5811,6 +5811,7 @@ upb_FindUnknownRet upb_MiniTable_FindUnknown(const upb_Message* msg,
   return ret;
 }
 
+// Warning: See TODO(b/267655898)
 upb_UnknownToMessageRet upb_MiniTable_PromoteUnknownToMessage(
     upb_Message* msg, const upb_MiniTable* mini_table,
     const upb_MiniTableField* field, const upb_MiniTable* sub_mini_table,
@@ -5821,7 +5822,10 @@ upb_UnknownToMessageRet upb_MiniTable_PromoteUnknownToMessage(
   // Callers should check that message is not set first before calling
   // PromotoUnknownToMessage.
   UPB_ASSERT(mini_table->subs[field->submsg_index].submsg == sub_mini_table);
-  UPB_ASSERT(upb_Message_GetMessage(msg, field, NULL) == NULL);
+  bool is_oneof = _upb_MiniTableField_InOneOf(field);
+  if (!is_oneof || _upb_getoneofcase_field(msg, field) == field->number) {
+    UPB_ASSERT(upb_Message_GetMessage(msg, field, NULL) == NULL);
+  }
   upb_UnknownToMessageRet ret;
   ret.status = kUpb_UnknownToMessage_Ok;
   do {
@@ -5849,6 +5853,9 @@ upb_UnknownToMessageRet upb_MiniTable_PromoteUnknownToMessage(
     }
   } while (unknown.status == kUpb_FindUnknown_Ok);
   if (message) {
+    if (is_oneof) {
+      *_upb_oneofcase_field(msg, field) = field->number;
+    }
     upb_Message_SetMessage(msg, mini_table, field, message);
     ret.message = message;
   }
@@ -6170,6 +6177,38 @@ upb_FieldType upb_MiniTableField_Type(const upb_MiniTableField* field) {
   return field->descriptortype;
 }
 
+static bool upb_MiniTable_Is_Oneof(const upb_MiniTableField* f) {
+  return f->presence < 0;
+}
+
+const upb_MiniTableField* upb_MiniTable_GetOneof(const upb_MiniTable* m,
+                                                 const upb_MiniTableField* f) {
+  if (UPB_UNLIKELY(!upb_MiniTable_Is_Oneof(f))) {
+    return NULL;
+  }
+  const upb_MiniTableField* ptr = &m->fields[0];
+  const upb_MiniTableField* end = &m->fields[m->field_count];
+  while (++ptr < end) {
+    if (ptr->presence == (*f).presence) {
+      return ptr;
+    }
+  }
+  return NULL;
+}
+
+bool upb_MiniTable_NextOneofField(const upb_MiniTable* m,
+                                  const upb_MiniTableField** f) {
+  const upb_MiniTableField* ptr = *f;
+  const upb_MiniTableField* end = &m->fields[m->field_count];
+  while (++ptr < end) {
+    if (ptr->presence == (*f)->presence) {
+      *f = ptr;
+      return true;
+    }
+  }
+  return false;
+}
+
 
 #include <inttypes.h>
 #include <stdlib.h>
diff --git a/php/ext/google/protobuf/php-upb.h b/php/ext/google/protobuf/php-upb.h
index f17a2dd827..6b554cc342 100644
--- a/php/ext/google/protobuf/php-upb.h
+++ b/php/ext/google/protobuf/php-upb.h
@@ -2253,6 +2253,26 @@ UPB_API_INLINE const upb_MiniTableEnum* upb_MiniTable_GetSubEnumTable(
   return mini_table->subs[field->submsg_index].subenum;
 }
 
+// If this field is in a oneof, returns the first field in the oneof.
+//
+// Otherwise returns NULL.
+//
+// Usage:
+//   const upb_MiniTableField* field = upb_MiniTable_GetOneof(m, f);
+//   do {
+//       ..
+//   } while (upb_MiniTable_NextOneofField(m, &field);
+//
+const upb_MiniTableField* upb_MiniTable_GetOneof(const upb_MiniTable* m,
+                                                 const upb_MiniTableField* f);
+
+// Returns the next field in the oneof. If this is the last field in the
+// oneof, returns NULL. The ordering of fields in the oneof is not
+// guaranteed.
+// REQUIRES: |iter| is and iterator.
+bool upb_MiniTable_NextOneofField(const upb_MiniTable* m,
+                                  const upb_MiniTableField** f);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
@@ -2942,6 +2962,8 @@ typedef struct {
 //
 // The unknown data is removed from message after field value is set
 // using upb_Message_SetMessage.
+//
+// WARNING!: See b/267655898
 upb_UnknownToMessageRet upb_MiniTable_PromoteUnknownToMessage(
     upb_Message* msg, const upb_MiniTable* mini_table,
     const upb_MiniTableField* field, const upb_MiniTable* sub_mini_table,
@@ -3289,6 +3311,12 @@ extern const upb_MiniTable google_protobuf_SourceCodeInfo_Location_msg_init;
 extern const upb_MiniTable google_protobuf_GeneratedCodeInfo_msg_init;
 extern const upb_MiniTable google_protobuf_GeneratedCodeInfo_Annotation_msg_init;
 
+typedef enum {
+  google_protobuf_FieldDescriptorProto_LABEL_OPTIONAL = 1,
+  google_protobuf_FieldDescriptorProto_LABEL_REQUIRED = 2,
+  google_protobuf_FieldDescriptorProto_LABEL_REPEATED = 3
+} google_protobuf_FieldDescriptorProto_Label;
+
 typedef enum {
   google_protobuf_FieldDescriptorProto_TYPE_DOUBLE = 1,
   google_protobuf_FieldDescriptorProto_TYPE_FLOAT = 2,
@@ -3310,18 +3338,6 @@ typedef enum {
   google_protobuf_FieldDescriptorProto_TYPE_SINT64 = 18
 } google_protobuf_FieldDescriptorProto_Type;
 
-typedef enum {
-  google_protobuf_FieldDescriptorProto_LABEL_OPTIONAL = 1,
-  google_protobuf_FieldDescriptorProto_LABEL_REQUIRED = 2,
-  google_protobuf_FieldDescriptorProto_LABEL_REPEATED = 3
-} google_protobuf_FieldDescriptorProto_Label;
-
-typedef enum {
-  google_protobuf_FileOptions_SPEED = 1,
-  google_protobuf_FileOptions_CODE_SIZE = 2,
-  google_protobuf_FileOptions_LITE_RUNTIME = 3
-} google_protobuf_FileOptions_OptimizeMode;
-
 typedef enum {
   google_protobuf_FieldOptions_STRING = 0,
   google_protobuf_FieldOptions_CORD = 1,
@@ -3354,10 +3370,10 @@ typedef enum {
 } google_protobuf_FieldOptions_OptionTargetType;
 
 typedef enum {
-  google_protobuf_MethodOptions_IDEMPOTENCY_UNKNOWN = 0,
-  google_protobuf_MethodOptions_NO_SIDE_EFFECTS = 1,
-  google_protobuf_MethodOptions_IDEMPOTENT = 2
-} google_protobuf_MethodOptions_IdempotencyLevel;
+  google_protobuf_FileOptions_SPEED = 1,
+  google_protobuf_FileOptions_CODE_SIZE = 2,
+  google_protobuf_FileOptions_LITE_RUNTIME = 3
+} google_protobuf_FileOptions_OptimizeMode;
 
 typedef enum {
   google_protobuf_GeneratedCodeInfo_Annotation_NONE = 0,
@@ -3365,16 +3381,22 @@ typedef enum {
   google_protobuf_GeneratedCodeInfo_Annotation_ALIAS = 2
 } google_protobuf_GeneratedCodeInfo_Annotation_Semantic;
 
+typedef enum {
+  google_protobuf_MethodOptions_IDEMPOTENCY_UNKNOWN = 0,
+  google_protobuf_MethodOptions_NO_SIDE_EFFECTS = 1,
+  google_protobuf_MethodOptions_IDEMPOTENT = 2
+} google_protobuf_MethodOptions_IdempotencyLevel;
+
 
-extern const upb_MiniTableEnum google_protobuf_FieldDescriptorProto_Type_enum_init;
 extern const upb_MiniTableEnum google_protobuf_FieldDescriptorProto_Label_enum_init;
-extern const upb_MiniTableEnum google_protobuf_FileOptions_OptimizeMode_enum_init;
+extern const upb_MiniTableEnum google_protobuf_FieldDescriptorProto_Type_enum_init;
 extern const upb_MiniTableEnum google_protobuf_FieldOptions_CType_enum_init;
 extern const upb_MiniTableEnum google_protobuf_FieldOptions_JSType_enum_init;
 extern const upb_MiniTableEnum google_protobuf_FieldOptions_OptionRetention_enum_init;
 extern const upb_MiniTableEnum google_protobuf_FieldOptions_OptionTargetType_enum_init;
-extern const upb_MiniTableEnum google_protobuf_MethodOptions_IdempotencyLevel_enum_init;
+extern const upb_MiniTableEnum google_protobuf_FileOptions_OptimizeMode_enum_init;
 extern const upb_MiniTableEnum google_protobuf_GeneratedCodeInfo_Annotation_Semantic_enum_init;
+extern const upb_MiniTableEnum google_protobuf_MethodOptions_IdempotencyLevel_enum_init;
 
 /* google.protobuf.FileDescriptorSet */
 
diff --git a/protobuf_deps.bzl b/protobuf_deps.bzl
index 18439ab126..fee1e9c1b1 100644
--- a/protobuf_deps.bzl
+++ b/protobuf_deps.bzl
@@ -149,7 +149,7 @@ def protobuf_deps():
         _github_archive(
             name = "upb",
             repo = "https://github.com/protocolbuffers/upb",
-            commit = "84a3fd2d2d943c8ff37f09feadb1dd3f60f954ee",
-            sha256 = "5c144471b9d92250e77710376251a6929e47b49eea50b8f380e759a9447fb60b",
+            commit = "662497f1d3dcced2bba1620cea9aae8b484bd3cd",
+            sha256 = "57c87ca4145d2cbc162a6c613b114b9325b577f4f6525bd78747a34b3d03627c",
             patches = ["@com_google_protobuf//build_defs:upb.patch"],
         )
diff --git a/ruby/ext/google/protobuf_c/ruby-upb.c b/ruby/ext/google/protobuf_c/ruby-upb.c
index 47636836b5..6fbf78bc02 100644
--- a/ruby/ext/google/protobuf_c/ruby-upb.c
+++ b/ruby/ext/google/protobuf_c/ruby-upb.c
@@ -5448,6 +5448,7 @@ upb_FindUnknownRet upb_MiniTable_FindUnknown(const upb_Message* msg,
   return ret;
 }
 
+// Warning: See TODO(b/267655898)
 upb_UnknownToMessageRet upb_MiniTable_PromoteUnknownToMessage(
     upb_Message* msg, const upb_MiniTable* mini_table,
     const upb_MiniTableField* field, const upb_MiniTable* sub_mini_table,
@@ -5458,7 +5459,10 @@ upb_UnknownToMessageRet upb_MiniTable_PromoteUnknownToMessage(
   // Callers should check that message is not set first before calling
   // PromotoUnknownToMessage.
   UPB_ASSERT(mini_table->subs[field->submsg_index].submsg == sub_mini_table);
-  UPB_ASSERT(upb_Message_GetMessage(msg, field, NULL) == NULL);
+  bool is_oneof = _upb_MiniTableField_InOneOf(field);
+  if (!is_oneof || _upb_getoneofcase_field(msg, field) == field->number) {
+    UPB_ASSERT(upb_Message_GetMessage(msg, field, NULL) == NULL);
+  }
   upb_UnknownToMessageRet ret;
   ret.status = kUpb_UnknownToMessage_Ok;
   do {
@@ -5486,6 +5490,9 @@ upb_UnknownToMessageRet upb_MiniTable_PromoteUnknownToMessage(
     }
   } while (unknown.status == kUpb_FindUnknown_Ok);
   if (message) {
+    if (is_oneof) {
+      *_upb_oneofcase_field(msg, field) = field->number;
+    }
     upb_Message_SetMessage(msg, mini_table, field, message);
     ret.message = message;
   }
@@ -5807,6 +5814,38 @@ upb_FieldType upb_MiniTableField_Type(const upb_MiniTableField* field) {
   return field->descriptortype;
 }
 
+static bool upb_MiniTable_Is_Oneof(const upb_MiniTableField* f) {
+  return f->presence < 0;
+}
+
+const upb_MiniTableField* upb_MiniTable_GetOneof(const upb_MiniTable* m,
+                                                 const upb_MiniTableField* f) {
+  if (UPB_UNLIKELY(!upb_MiniTable_Is_Oneof(f))) {
+    return NULL;
+  }
+  const upb_MiniTableField* ptr = &m->fields[0];
+  const upb_MiniTableField* end = &m->fields[m->field_count];
+  while (++ptr < end) {
+    if (ptr->presence == (*f).presence) {
+      return ptr;
+    }
+  }
+  return NULL;
+}
+
+bool upb_MiniTable_NextOneofField(const upb_MiniTable* m,
+                                  const upb_MiniTableField** f) {
+  const upb_MiniTableField* ptr = *f;
+  const upb_MiniTableField* end = &m->fields[m->field_count];
+  while (++ptr < end) {
+    if (ptr->presence == (*f)->presence) {
+      *f = ptr;
+      return true;
+    }
+  }
+  return false;
+}
+
 
 #include <inttypes.h>
 #include <stdlib.h>
diff --git a/ruby/ext/google/protobuf_c/ruby-upb.h b/ruby/ext/google/protobuf_c/ruby-upb.h
index 7d01e6c986..cd703c288f 100755
--- a/ruby/ext/google/protobuf_c/ruby-upb.h
+++ b/ruby/ext/google/protobuf_c/ruby-upb.h
@@ -2255,6 +2255,26 @@ UPB_API_INLINE const upb_MiniTableEnum* upb_MiniTable_GetSubEnumTable(
   return mini_table->subs[field->submsg_index].subenum;
 }
 
+// If this field is in a oneof, returns the first field in the oneof.
+//
+// Otherwise returns NULL.
+//
+// Usage:
+//   const upb_MiniTableField* field = upb_MiniTable_GetOneof(m, f);
+//   do {
+//       ..
+//   } while (upb_MiniTable_NextOneofField(m, &field);
+//
+const upb_MiniTableField* upb_MiniTable_GetOneof(const upb_MiniTable* m,
+                                                 const upb_MiniTableField* f);
+
+// Returns the next field in the oneof. If this is the last field in the
+// oneof, returns NULL. The ordering of fields in the oneof is not
+// guaranteed.
+// REQUIRES: |iter| is and iterator.
+bool upb_MiniTable_NextOneofField(const upb_MiniTable* m,
+                                  const upb_MiniTableField** f);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
@@ -2944,6 +2964,8 @@ typedef struct {
 //
 // The unknown data is removed from message after field value is set
 // using upb_Message_SetMessage.
+//
+// WARNING!: See b/267655898
 upb_UnknownToMessageRet upb_MiniTable_PromoteUnknownToMessage(
     upb_Message* msg, const upb_MiniTable* mini_table,
     const upb_MiniTableField* field, const upb_MiniTable* sub_mini_table,
@@ -3291,6 +3313,12 @@ extern const upb_MiniTable google_protobuf_SourceCodeInfo_Location_msg_init;
 extern const upb_MiniTable google_protobuf_GeneratedCodeInfo_msg_init;
 extern const upb_MiniTable google_protobuf_GeneratedCodeInfo_Annotation_msg_init;
 
+typedef enum {
+  google_protobuf_FieldDescriptorProto_LABEL_OPTIONAL = 1,
+  google_protobuf_FieldDescriptorProto_LABEL_REQUIRED = 2,
+  google_protobuf_FieldDescriptorProto_LABEL_REPEATED = 3
+} google_protobuf_FieldDescriptorProto_Label;
+
 typedef enum {
   google_protobuf_FieldDescriptorProto_TYPE_DOUBLE = 1,
   google_protobuf_FieldDescriptorProto_TYPE_FLOAT = 2,
@@ -3312,18 +3340,6 @@ typedef enum {
   google_protobuf_FieldDescriptorProto_TYPE_SINT64 = 18
 } google_protobuf_FieldDescriptorProto_Type;
 
-typedef enum {
-  google_protobuf_FieldDescriptorProto_LABEL_OPTIONAL = 1,
-  google_protobuf_FieldDescriptorProto_LABEL_REQUIRED = 2,
-  google_protobuf_FieldDescriptorProto_LABEL_REPEATED = 3
-} google_protobuf_FieldDescriptorProto_Label;
-
-typedef enum {
-  google_protobuf_FileOptions_SPEED = 1,
-  google_protobuf_FileOptions_CODE_SIZE = 2,
-  google_protobuf_FileOptions_LITE_RUNTIME = 3
-} google_protobuf_FileOptions_OptimizeMode;
-
 typedef enum {
   google_protobuf_FieldOptions_STRING = 0,
   google_protobuf_FieldOptions_CORD = 1,
@@ -3356,10 +3372,10 @@ typedef enum {
 } google_protobuf_FieldOptions_OptionTargetType;
 
 typedef enum {
-  google_protobuf_MethodOptions_IDEMPOTENCY_UNKNOWN = 0,
-  google_protobuf_MethodOptions_NO_SIDE_EFFECTS = 1,
-  google_protobuf_MethodOptions_IDEMPOTENT = 2
-} google_protobuf_MethodOptions_IdempotencyLevel;
+  google_protobuf_FileOptions_SPEED = 1,
+  google_protobuf_FileOptions_CODE_SIZE = 2,
+  google_protobuf_FileOptions_LITE_RUNTIME = 3
+} google_protobuf_FileOptions_OptimizeMode;
 
 typedef enum {
   google_protobuf_GeneratedCodeInfo_Annotation_NONE = 0,
@@ -3367,16 +3383,22 @@ typedef enum {
   google_protobuf_GeneratedCodeInfo_Annotation_ALIAS = 2
 } google_protobuf_GeneratedCodeInfo_Annotation_Semantic;
 
+typedef enum {
+  google_protobuf_MethodOptions_IDEMPOTENCY_UNKNOWN = 0,
+  google_protobuf_MethodOptions_NO_SIDE_EFFECTS = 1,
+  google_protobuf_MethodOptions_IDEMPOTENT = 2
+} google_protobuf_MethodOptions_IdempotencyLevel;
+
 
-extern const upb_MiniTableEnum google_protobuf_FieldDescriptorProto_Type_enum_init;
 extern const upb_MiniTableEnum google_protobuf_FieldDescriptorProto_Label_enum_init;
-extern const upb_MiniTableEnum google_protobuf_FileOptions_OptimizeMode_enum_init;
+extern const upb_MiniTableEnum google_protobuf_FieldDescriptorProto_Type_enum_init;
 extern const upb_MiniTableEnum google_protobuf_FieldOptions_CType_enum_init;
 extern const upb_MiniTableEnum google_protobuf_FieldOptions_JSType_enum_init;
 extern const upb_MiniTableEnum google_protobuf_FieldOptions_OptionRetention_enum_init;
 extern const upb_MiniTableEnum google_protobuf_FieldOptions_OptionTargetType_enum_init;
-extern const upb_MiniTableEnum google_protobuf_MethodOptions_IdempotencyLevel_enum_init;
+extern const upb_MiniTableEnum google_protobuf_FileOptions_OptimizeMode_enum_init;
 extern const upb_MiniTableEnum google_protobuf_GeneratedCodeInfo_Annotation_Semantic_enum_init;
+extern const upb_MiniTableEnum google_protobuf_MethodOptions_IdempotencyLevel_enum_init;
 
 /* google.protobuf.FileDescriptorSet */