diff -up snack2.2.10/generic/jkSoundFile.c.CVE20126303 snack2.2.10/generic/jkSoundFile.c
--- snack2.2.10/generic/jkSoundFile.c.CVE20126303	2013-01-02 11:26:15.496231056 -0500
+++ snack2.2.10/generic/jkSoundFile.c	2013-01-02 11:27:26.134250662 -0500
@@ -1798,7 +1798,14 @@ static int
 GetHeaderBytes(Sound *s, Tcl_Interp *interp, Tcl_Channel ch, char *buf, 
 	       int len)
 {
-  int rlen = Tcl_Read(ch, &buf[s->firstNRead], len - s->firstNRead);
+  int rlen;
+
+  if (len > max(CHANNEL_HEADER_BUFFER, HEADBUF)){
+    Tcl_AppendResult(interp, "Excessive header size", NULL);
+    return TCL_ERROR;
+  }
+
+  rlen = Tcl_Read(ch, &buf[s->firstNRead], len - s->firstNRead);
 
   if (rlen < len - s->firstNRead){
     Tcl_AppendResult(interp, "Failed reading header bytes", NULL);