Kohana through 3.3.6 has SQL Injection when the order_by() parameter can be controlled.

CodeIgniter before 3.0 and Kohana 3.2.3 and earlier and 3.3.x through 3.3.2 make it easier for remote attackers to spoof session cookies and consequently conduct PHP object injection attacks by leveraging use of standard string comparison operators to compare cryptographic hashes.

Cross-site scripting (XSS) vulnerability in the Security component of Kohana before 3.3.6 allows remote attackers to inject arbitrary web script or HTML by bypassing the strip_image_tags protection mechanism in system/classes/Kohana/Security.php.