Index: wp-includes/functions.php
===================================================================
--- wp-includes/functions.php	(revision 12484)
+++ wp-includes/functions.php	(working copy)
@@ -257,7 +257,7 @@
 		case 'a' :
 		case 'O' :
 		case 's' :
-			if ( preg_match( "/^{$badions[1]}:[0-9]+:.*[;}]\$/s", $data ) )
+			if ( in_array(substr($data, -1), array(';', '}')) && preg_match( "/^{$badions[1]}:[0-9]+:/", $data ) )
 				return true;
 			break;
 		case 'b' :