--- mutt-1.5.21/signature.c~	2012-12-07 08:23:16.427880553 +0100
+++ mutt-1.5.21/signature.c	2012-12-07 08:24:37.171211039 +0100
@@ -292,7 +292,7 @@
   char* searchBuf = menu->menu >= 0 && menu->menu < MENU_MAX ?
                     SearchBuffers[menu->menu] : NULL;
 
-  snprintf (buf, sizeof(buf), searchBuf ? searchBuf : "");
+  snprintf (buf, sizeof(buf), "%s", searchBuf ? searchBuf : "");
   if (mutt_get_field (_("Search for: "), buf,
 		      sizeof (buf), M_CLEAR) != 0 || !buf[0])
     return (NULL);