Update NEWS

Author: Yasuo Ohgaki

NEWS

@@ -12,6 +12,7 @@ PHP                                                                        NEWS
 
 - Mbstring:
   . Fixed bug #72994 (mbc_to_code() out of bounds read). (Laruence, cmb)
+  . Fixed bug #66964 (mb_convert_variables() cannot detect recursion) (Yasuo)
 
 - Opcache:
   . Fixed bug #72590 (Opcache restart with kill_all_lockers does not work).