diff --git a/helper/ccnb-parser/syntax-tree/ccnb-parser-tag.cc b/helper/ccnb-parser/syntax-tree/ccnb-parser-tag.cc
index c288be9..5862ad4 100644
--- a/helper/ccnb-parser/syntax-tree/ccnb-parser-tag.cc
+++ b/helper/ccnb-parser/syntax-tree/ccnb-parser-tag.cc
@@ -28,10 +28,13 @@
 Tag::Tag (Buffer::Iterator &start, uint32_t length)
 {
   m_tag.reserve (length+2); // extra byte for potential \0 at the end
-  for (uint32_t i = 0; i < (length+1); i++)
+  uint32_t i = 0;
+  for (; !start.IsEnd () && i < (length+1); i++)
     {
       m_tag.push_back (start.ReadU8 ());
     }
+  if (i < (length+1) && start.IsEnd ())
+    throw CcnbDecodingException ();
   
   // parse attributes until first nested block reached
   while (!start.IsEnd () && start.PeekU8 ()!=CCN_CLOSE)