The "Remember me" feature in the opSecurityUser::getRememberLoginCookie function in lib/user/opSecurityUser.class.php in OpenPNE 3.6.13 before 3.6.13.1 and 3.8.9 before 3.8.9.1 does not properly validate login data in HTTP Cookie headers, which allows remote attackers to conduct PHP object injection attacks, and execute arbitrary PHP code, via a crafted serialized object.