diff --git a/lib/cpp/src/thrift/protocol/TJSONProtocol.cpp b/lib/cpp/src/thrift/protocol/TJSONProtocol.cpp
index 3805869..1218190 100644
--- a/lib/cpp/src/thrift/protocol/TJSONProtocol.cpp
+++ b/lib/cpp/src/thrift/protocol/TJSONProtocol.cpp
@@ -1087,7 +1087,10 @@
 uint32_t TJSONProtocol::readByte(int8_t& byte) {
   auto tmp = (int16_t)byte;
   uint32_t result = readJSONInteger(tmp);
-  assert(tmp < 256);
+  if (tmp > 127 || tmp < -128) {
+    throw TProtocolException(TProtocolException::INVALID_DATA,
+                            "Expected byte value; got " + to_string(tmp));
+  }
   byte = (int8_t)tmp;
   return result;
 }
diff --git a/lib/cpp/test/JSONProtoTest.cpp b/lib/cpp/test/JSONProtoTest.cpp
index ef39385..1874ccd 100644
--- a/lib/cpp/test/JSONProtoTest.cpp
+++ b/lib/cpp/test/JSONProtoTest.cpp
@@ -366,3 +366,16 @@
   BOOST_CHECK_THROW(ooe2.read(proto.get()),
     apache::thrift::protocol::TProtocolException);
 }
+
+BOOST_AUTO_TEST_CASE(test_json_invalid_byte_range) {
+  // Test case for byte values outside valid range
+  const char json_string[] = "\"3\":{\"i8\":849}";
+
+  std::shared_ptr<TMemoryBuffer> buffer(new TMemoryBuffer(
+    (uint8_t*)(json_string), sizeof(json_string)));
+  std::shared_ptr<TJSONProtocol> proto(new TJSONProtocol(buffer));
+
+  OneOfEach ooe2;
+  BOOST_CHECK_THROW(ooe2.read(proto.get()),
+    apache::thrift::protocol::TProtocolException);
+}