diff --git a/esphome/components/mqtt/custom_mqtt_device.cpp b/esphome/components/mqtt/custom_mqtt_device.cpp
index 5ad71dbdb0..7ff65bb42c 100644
--- a/esphome/components/mqtt/custom_mqtt_device.cpp
+++ b/esphome/components/mqtt/custom_mqtt_device.cpp
@@ -18,7 +18,7 @@ bool CustomMQTTDevice::publish(const std::string &topic, float value, int8_t num
 }
 bool CustomMQTTDevice::publish(const std::string &topic, int value) {
   char buffer[24];
-  int len = sprintf(buffer, "%d", value);
+  int len = snprintf(buffer, sizeof(buffer), "%d", value);
   return global_mqtt_client->publish(topic, buffer, len);
 }
 bool CustomMQTTDevice::publish_json(const std::string &topic, const json::json_build_t &f, uint8_t qos, bool retain) {
diff --git a/esphome/components/mqtt/mqtt_fan.cpp b/esphome/components/mqtt/mqtt_fan.cpp
index 4ffd043a96..a6f0503588 100644
--- a/esphome/components/mqtt/mqtt_fan.cpp
+++ b/esphome/components/mqtt/mqtt_fan.cpp
@@ -174,7 +174,7 @@ bool MQTTFanComponent::publish_state() {
   }
   auto traits = this->state_->get_traits();
   if (traits.supports_speed()) {
-    char buf[4];
+    char buf[12];
     int len = snprintf(buf, sizeof(buf), "%d", this->state_->speed);
     bool success = this->publish(this->get_speed_level_state_topic(), buf, len);
     failed = failed || !success;
diff --git a/esphome/components/wifi/wifi_component_esp8266.cpp b/esphome/components/wifi/wifi_component_esp8266.cpp
index b7d820413c..61c4584d09 100644
--- a/esphome/components/wifi/wifi_component_esp8266.cpp
+++ b/esphome/components/wifi/wifi_component_esp8266.cpp
@@ -543,7 +543,12 @@ void WiFiComponent::wifi_event_callback(System_Event_t *event) {
       }
       s_sta_connected = false;
       s_sta_connecting = false;
+      // IMPORTANT: Set error flag BEFORE notifying listeners.
+      // This ensures is_connected() returns false during listener callbacks,
+      // which is critical for proper reconnection logic (e.g., roaming).
+      global_wifi_component->error_from_callback_ = true;
 #ifdef USE_WIFI_LISTENERS
+      // Notify listeners AFTER setting error flag so they see correct state
       static constexpr uint8_t EMPTY_BSSID[6] = {};
       for (auto *listener : global_wifi_component->connect_state_listeners_) {
         listener->on_wifi_connect_state(StringRef(), EMPTY_BSSID);
@@ -635,10 +640,6 @@ void WiFiComponent::wifi_event_callback(System_Event_t *event) {
       break;
   }
 
-  if (event->event == EVENT_STAMODE_DISCONNECTED) {
-    global_wifi_component->error_from_callback_ = true;
-  }
-
   WiFiMockClass::_event_callback(event);
 }