Seo4SMF 2.9.10 was released.
Is just a security fix.
If you are afraid to upgrade just replace
$topic = $_GET['t']);
$board = $_GET['b'];
$other = $_GET['o'];
$user = $_GET['u'];
$tpage = $_GET['p'];
$action = $_GET['a'];
$param = $_GET['param'];
with
$topic = mysql_real_escape_string($_GET['t']);
$board = mysql_real_escape_string($_GET['b']);
$other = mysql_real_escape_string($_GET['o']);
$user = mysql_real_escape_string($_GET['u']);
$tpage = mysql_real_escape_string($_GET['p']);
$action = mysql_real_escape_string($_GET['a']);
$param = mysql_real_escape_string($_GET['param']);
in seo4smf-redirect.php
Regards