diff --git a/tasmota/tasmota_xdrv_driver/xdrv_10_scripter.ino b/tasmota/tasmota_xdrv_driver/xdrv_10_scripter.ino
index 98a9c352f..6e8f41d3c 100755
--- a/tasmota/tasmota_xdrv_driver/xdrv_10_scripter.ino
+++ b/tasmota/tasmota_xdrv_driver/xdrv_10_scripter.ino
@@ -9349,8 +9349,10 @@ bool Script_SubCmd(void) {
   cp += tlen;
   if (XdrvMailbox.data_len > 0) {
     *cp++ = '(';
-    strncpy(cp, XdrvMailbox.data,XdrvMailbox.data_len);
-    cp += XdrvMailbox.data_len;
+    uint32_t max_space = sizeof(cmdbuff) - tlen - 4;  // 4 = #()0
+    uint32_t max_len = min(XdrvMailbox.data_len, max_space);
+    strncpy(cp, XdrvMailbox.data, max_len);
+    cp += max_len;
     *cp++ = ')';
     *cp = 0;
   }