From 1460e1a68221fca854b7b1e278cab76e763c00e6 Mon Sep 17 00:00:00 2001
From: pennam <m.pennasilico@arduino.cc>
Date: Mon, 4 May 2026 12:19:04 +0200
Subject: [PATCH] check if data fits writeBuffer before copy

---
 src/utility/ATT.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/utility/ATT.cpp b/src/utility/ATT.cpp
index ba717543..8a46e37c 100644
--- a/src/utility/ATT.cpp
+++ b/src/utility/ATT.cpp
@@ -1314,6 +1314,10 @@ void ATTClass::writeReqOrCmd(uint16_t connectionHandle, uint16_t mtu, uint8_t op
           writeBuffer[writeBufferSize] = valueLength;
           writeBufferSize += sizeof(valueLength);
 
+          if (writeBufferSize + valueLength > sizeof(writeBuffer)) {
+            sendError(connectionHandle, op, handle, ATT_ECODE_INSUFF_RESOURCES);
+            return;
+          }
           memcpy(&writeBuffer[writeBufferSize], value, valueLength);
           writeBufferSize += valueLength;
         }else{