diff --git a/wled00/src/dependencies/espalexa/Espalexa.h b/wled00/src/dependencies/espalexa/Espalexa.h
index 0850ddea..5c780e24 100644
--- a/wled00/src/dependencies/espalexa/Espalexa.h
+++ b/wled00/src/dependencies/espalexa/Espalexa.h
@@ -10,7 +10,7 @@
  */
 /*
  * @title Espalexa library
- * @version 2.7.0
+ * @version 2.7.1
  * @author Christian Schwinne
  * @license MIT
  * @contributors d-999
@@ -50,7 +50,7 @@
 #include "../network/Network.h"
 
 #ifdef ESPALEXA_DEBUG
- #pragma message "Espalexa 2.7.0 debug mode"
+ #pragma message "Espalexa 2.7.1 debug mode"
  #define EA_DEBUG(x)  Serial.print (x)
  #define EA_DEBUGLN(x) Serial.println (x)
 #else
@@ -142,7 +142,7 @@ private:
   }
 
   //device JSON string: color+temperature device emulates LCT015, dimmable device LWB010, (TODO: on/off Plug 01, color temperature device LWT010, color device LST001)
-  void deviceJsonString(EspalexaDevice* dev, char* buf)
+  void deviceJsonString(EspalexaDevice* dev, char* buf, size_t maxBuf) // softhack007 "size" parameter added, to avoid buffer overrun
   {
     char buf_lightid[27];
     encodeLightId(dev->getId() + 1, buf_lightid);
@@ -153,19 +153,19 @@ private:
       //TODO: %f is not working for some reason on ESP8266 in v0.11.0 (was fine in 0.10.2). Need to investigate
       //sprintf_P(buf_col,PSTR(",\"hue\":%u,\"sat\":%u,\"effect\":\"none\",\"xy\":[%f,%f]")
       //  ,dev->getHue(), dev->getSat(), dev->getX(), dev->getY());
-      sprintf_P(buf_col,PSTR(",\"hue\":%u,\"sat\":%u,\"effect\":\"none\",\"xy\":[%s,%s]"),dev->getHue(), dev->getSat(),
+      snprintf_P(buf_col, sizeof(buf_col), PSTR(",\"hue\":%u,\"sat\":%u,\"effect\":\"none\",\"xy\":[%s,%s]"),dev->getHue(), dev->getSat(),
         ((String)dev->getX()).c_str(), ((String)dev->getY()).c_str());
       
     char buf_ct[16] = "";
     //white spectrum support
     if (static_cast<uint8_t>(dev->getType()) > 1 && dev->getType() != EspalexaDeviceType::color)
-      sprintf(buf_ct, ",\"ct\":%u", dev->getCt());
+      snprintf(buf_ct, sizeof(buf_ct), ",\"ct\":%u", dev->getCt());
     
     char buf_cm[20] = "";
     if (static_cast<uint8_t>(dev->getType()) > 1)
-      sprintf(buf_cm,PSTR("\",\"colormode\":\"%s"), modeString(dev->getColorMode()));
+      snprintf(buf_cm, sizeof(buf_cm), PSTR("\",\"colormode\":\"%s"), modeString(dev->getColorMode()));
     
-    sprintf_P(buf, PSTR("{\"state\":{\"on\":%s,\"bri\":%u%s%s,\"alert\":\"none%s\",\"mode\":\"homeautomation\",\"reachable\":true},"
+    snprintf_P(buf, maxBuf, PSTR("{\"state\":{\"on\":%s,\"bri\":%u%s%s,\"alert\":\"none%s\",\"mode\":\"homeautomation\",\"reachable\":true},"
                    "\"type\":\"%s\",\"name\":\"%s\",\"modelid\":\"%s\",\"manufacturername\":\"Philips\",\"productname\":\"E%u"
                    "\",\"uniqueid\":\"%s\",\"swversion\":\"espalexa-2.7.0\"}")
                    
@@ -219,10 +219,10 @@ private:
     EA_DEBUGLN("# Responding to description.xml ... #\n");
     IPAddress localIP = Network.localIP();
     char s[16];
-    sprintf(s, "%d.%d.%d.%d", localIP[0], localIP[1], localIP[2], localIP[3]);
+    snprintf(s, sizeof(s), "%d.%d.%d.%d", localIP[0], localIP[1], localIP[2], localIP[3]);
     char buf[1024];
     
-    sprintf_P(buf,PSTR("<?xml version=\"1.0\" ?>"
+    snprintf_P(buf, sizeof(buf), PSTR("<?xml version=\"1.0\" ?>"
         "<root xmlns=\"urn:schemas-upnp-org:device-1-0\">"
         "<specVersion><major>1</major><minor>0</minor></specVersion>"
         "<URLBase>http://%s:80/</URLBase>"
@@ -297,7 +297,7 @@ private:
 
     char buf[1024];
 
-    sprintf_P(buf,PSTR("HTTP/1.1 200 OK\r\n"
+    snprintf_P(buf, sizeof(buf), PSTR("HTTP/1.1 200 OK\r\n"
       "EXT:\r\n"
       "CACHE-CONTROL: max-age=100\r\n" // SSDP_INTERVAL
       "LOCATION: http://%s:80/description.xml\r\n"
@@ -493,7 +493,7 @@ public:
       unsigned idx = decodeLightKey(devId);
       EA_DEBUGLN(idx);
       char buf[50];
-      sprintf_P(buf,PSTR("[{\"success\":{\"/lights/%u/state/\": true}}]"),devId);
+      snprintf_P(buf,sizeof(buf),PSTR("[{\"success\":{\"/lights/%u/state/\": true}}]"),devId);
       server->send(200, "application/json", buf);
       if (idx >= currentDeviceCount) return true; //return if invalid ID
       EspalexaDevice* dev = devices[idx];
@@ -571,7 +571,7 @@ public:
           jsonTemp += ':';
 
           char buf[512];
-          deviceJsonString(devices[i], buf);
+          deviceJsonString(devices[i], buf, sizeof(buf)-1);
           jsonTemp += buf;
           if (i < currentDeviceCount-1) jsonTemp += ',';
         }
@@ -588,7 +588,7 @@ public:
           return true;
         }
         char buf[512];
-        deviceJsonString(devices[idx], buf);
+        deviceJsonString(devices[idx], buf, sizeof(buf)-1);
         server->send(200, "application/json", buf);
       }
       
diff --git a/wled00/src/dependencies/espalexa/EspalexaDevice.cpp b/wled00/src/dependencies/espalexa/EspalexaDevice.cpp
index fa643491..407a9d61 100644
--- a/wled00/src/dependencies/espalexa/EspalexaDevice.cpp
+++ b/wled00/src/dependencies/espalexa/EspalexaDevice.cpp
@@ -2,6 +2,15 @@
 
 #include "EspalexaDevice.h"
 
+// debug macros
+#ifdef ESPALEXA_DEBUG
+ #define EA_DEBUG(x)  Serial.print (x)
+ #define EA_DEBUGLN(x) Serial.println (x)
+#else
+ #define EA_DEBUG(x)
+ #define EA_DEBUGLN(x)
+#endif
+
 EspalexaDevice::EspalexaDevice(){}
 
 EspalexaDevice::EspalexaDevice(String deviceName, BrightnessCallbackFunction gnCallback, uint8_t initialValue) { //constructor for dimmable device
@@ -124,18 +133,21 @@ uint32_t EspalexaDevice::getRGB()
   {
     //TODO tweak a bit to match hue lamp characteristics
     //based on https://gist.github.com/paulkaplan/5184275
-    float temp = 10000/ _ct; //kelvins = 1,000,000/mired (and that /100)
+    float temp = (_ct != 0) ? (10000/ _ct) : 2; //kelvins = 1,000,000/mired (and that /100)   softhack007: avoid division by zero - using "2" as substitute
     float r, g, b;
 
+#ifdef ESPALEXA_DEBUG
+  if (_ct == 0) {EA_DEBUGLN(F("EspalexaDevice::getRGB() Warning: ct = 0!"));}
+#endif
     if (temp <= 66) { 
       r = 255; 
       g = temp;
-      g = 99.470802 * log(g) - 161.119568;
+      g = 99.470802 * logf(g) - 161.119568;
       if (temp <= 19) {
           b = 0;
       } else {
           b = temp-10;
-          b = 138.517731 * log(b) - 305.044793;
+          b = 138.517731 * logf(b) - 305.044793;
       }
     } else {
       r = temp - 60;
@@ -192,9 +204,9 @@ uint32_t EspalexaDevice::getRGB()
       b = 1.0f;
     }
     // Apply gamma correction
-    r = r <= 0.0031308f ? 12.92f * r : (1.0f + 0.055f) * pow(r, (1.0f / 2.4f)) - 0.055f;
-    g = g <= 0.0031308f ? 12.92f * g : (1.0f + 0.055f) * pow(g, (1.0f / 2.4f)) - 0.055f;
-    b = b <= 0.0031308f ? 12.92f * b : (1.0f + 0.055f) * pow(b, (1.0f / 2.4f)) - 0.055f;
+    r = r <= 0.0031308f ? 12.92f * r : (1.0f + 0.055f) * powf(r, (1.0f / 2.4f)) - 0.055f;
+    g = g <= 0.0031308f ? 12.92f * g : (1.0f + 0.055f) * powf(g, (1.0f / 2.4f)) - 0.055f;
+    b = b <= 0.0031308f ? 12.92f * b : (1.0f + 0.055f) * powf(b, (1.0f / 2.4f)) - 0.055f;
 
     if (r > b && r > g) {
       // red is biggest
@@ -328,8 +340,10 @@ void EspalexaDevice::setColor(uint8_t r, uint8_t g, uint8_t b)
   float X = r * 0.664511f + g * 0.154324f + b * 0.162028f;
   float Y = r * 0.283881f + g * 0.668433f + b * 0.047685f;
   float Z = r * 0.000088f + g * 0.072310f + b * 0.986039f;
-  _x = X / (X + Y + Z);
-  _y = Y / (X + Y + Z);
+  if ((r+g+b) > 0) { //   softhack007: avoid division by zero
+    _x = X / (X + Y + Z);
+    _y = Y / (X + Y + Z);
+  } else { _x = _y = 0.5f;}  // softhack007: use default values in case of "black"
   _rgb = ((r << 16) | (g << 8) | b);
   _mode = EspalexaColorMode::xy;
 }