diff --git a/esphome/core/helpers.cpp b/esphome/core/helpers.cpp
index 3e614eb515..37d9cdc24b 100644
--- a/esphome/core/helpers.cpp
+++ b/esphome/core/helpers.cpp
@@ -48,13 +48,13 @@ void get_mac_address_raw(uint8_t *mac) {
 std::string get_mac_address() {
   uint8_t mac[6];
   get_mac_address_raw(mac);
-  return str_sprintf("%02x%02x%02x%02x%02x%02x", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+  return str_snprintf("%02x%02x%02x%02x%02x%02x", 12, mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
 }
 
 std::string get_mac_address_pretty() {
   uint8_t mac[6];
   get_mac_address_raw(mac);
-  return str_sprintf("%02X:%02X:%02X:%02X:%02X:%02X", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+  return str_snprintf("%02X:%02X:%02X:%02X:%02X:%02X", 17, mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
 }
 
 #ifdef USE_ESP32
@@ -325,6 +325,20 @@ bool str_startswith(const std::string &full, const std::string &start) { return
 bool str_endswith(const std::string &full, const std::string &ending) {
   return full.rfind(ending) == (full.size() - ending.size());
 }
+std::string str_snprintf(const char *fmt, size_t length, ...) {
+  std::string str;
+  va_list args;
+
+  str.resize(length);
+  va_start(args, length);
+  size_t out_length = vsnprintf(&str[0], length + 1, fmt, args);
+  va_end(args);
+
+  if (out_length < length)
+    str.resize(out_length);
+
+  return str;
+}
 std::string str_sprintf(const char *fmt, ...) {
   std::string str;
   va_list args;
diff --git a/esphome/core/helpers.h b/esphome/core/helpers.h
index 120642c62e..4ce1f08074 100644
--- a/esphome/core/helpers.h
+++ b/esphome/core/helpers.h
@@ -57,7 +57,10 @@ bool str_equals_case_insensitive(const std::string &a, const std::string &b);
 bool str_startswith(const std::string &full, const std::string &start);
 bool str_endswith(const std::string &full, const std::string &ending);
 
-/// sprintf-like function returning std::string instead of writing to char array.
+/// snprintf-like function returning std::string with a given maximum length.
+std::string __attribute__((format(printf, 1, 3))) str_snprintf(const char *fmt, size_t length, ...);
+
+/// sprintf-like function returning std::string.
 std::string __attribute__((format(printf, 1, 2))) str_sprintf(const char *fmt, ...);
 
 class HighFrequencyLoopRequester {