Possible DOS attack with long user-submitted passwords

Request::getHost() poisoning

php-symfony2-Validator has loss of information during serialization

CVE-2015-8125: Potential Remote Timing Attack Vulnerability in Security Remember-Me Service

A session fixation vulnerability within the "Remember Me" login feature allows an attacker to impersonate the victim towards the web application if the session id value was previously known to the attacker. This issue has been fixed in Symfony 2.3.35, 2.6.12, and 2.7.7. Note that no fixes are provided for Symfony 2.4 and 2.5 as they are not maintained anymore. Symfony 2.8 and 3.0 haven't been released yet and the fix will be included in their first stable releases.