diff --git a/esphome/components/ds2484/ds2484.cpp b/esphome/components/ds2484/ds2484.cpp
index 7c890ff433..0b36f86874 100644
--- a/esphome/components/ds2484/ds2484.cpp
+++ b/esphome/components/ds2484/ds2484.cpp
@@ -110,9 +110,9 @@ uint8_t DS2484OneWireBus::read8() {
 }
 
 uint64_t DS2484OneWireBus::read64() {
-  uint8_t response = 0;
+  uint64_t response = 0;
   for (uint8_t i = 0; i < 8; i++) {
-    response |= (this->read8() << (i * 8));
+    response |= (static_cast<uint64_t>(this->read8()) << (i * 8));
   }
   return response;
 }
diff --git a/esphome/components/sgp30/sgp30.cpp b/esphome/components/sgp30/sgp30.cpp
index 18814405d4..35e5b3dd42 100644
--- a/esphome/components/sgp30/sgp30.cpp
+++ b/esphome/components/sgp30/sgp30.cpp
@@ -41,7 +41,9 @@ void SGP30Component::setup() {
     this->mark_failed();
     return;
   }
-  this->serial_number_ = encode_uint24(raw_serial_number[0], raw_serial_number[1], raw_serial_number[2]);
+  this->serial_number_ = (static_cast<uint64_t>(raw_serial_number[0]) << 32) |
+                         (static_cast<uint64_t>(raw_serial_number[1]) << 16) |
+                         static_cast<uint64_t>(raw_serial_number[2]);
   ESP_LOGD(TAG, "Serial number: %" PRIu64, this->serial_number_);
 
   // Featureset identification for future use
diff --git a/esphome/components/zwave_proxy/zwave_proxy.cpp b/esphome/components/zwave_proxy/zwave_proxy.cpp
index a6fb453ae5..9e5c57814d 100644
--- a/esphome/components/zwave_proxy/zwave_proxy.cpp
+++ b/esphome/components/zwave_proxy/zwave_proxy.cpp
@@ -281,6 +281,10 @@ bool ZWaveProxy::parse_byte_(uint8_t byte) {
       break;
     }
     case ZWAVE_PARSING_STATE_READ_BL_MENU:
+      if (this->buffer_index_ >= this->buffer_.size()) {
+        this->parsing_state_ = ZWAVE_PARSING_STATE_WAIT_START;
+        break;
+      }
       this->buffer_[this->buffer_index_++] = byte;
       if (!byte) {
         this->parsing_state_ = ZWAVE_PARSING_STATE_WAIT_START;
diff --git a/esphome/components/zwave_proxy/zwave_proxy.h b/esphome/components/zwave_proxy/zwave_proxy.h
index eb26316f49..12cb9a90a1 100644
--- a/esphome/components/zwave_proxy/zwave_proxy.h
+++ b/esphome/components/zwave_proxy/zwave_proxy.h
@@ -81,10 +81,10 @@ class ZWaveProxy : public uart::UARTDevice, public Component {
   api::APIConnection *api_connection_{nullptr};  // Current subscribed client
   uint32_t setup_time_{0};                       // Time when setup() was called
 
-  // 8-bit values (grouped together to minimize padding)
-  uint8_t buffer_index_{0};     // Index for populating the data buffer
-  uint8_t end_frame_after_{0};  // Payload reception ends after this index
-  uint8_t last_response_{0};    // Last response type sent
+  // Small values (grouped by size to minimize padding)
+  uint16_t buffer_index_{0};     // Index for populating the data buffer
+  uint16_t end_frame_after_{0};  // Payload reception ends after this index
+  uint8_t last_response_{0};     // Last response type sent
   ZWaveParsingState parsing_state_{ZWAVE_PARSING_STATE_WAIT_START};
   bool in_bootloader_{false};  // True if the device is detected to be in bootloader mode
   bool home_id_ready_{false};  // True when home ID has been received from Z-Wave module