LORIS (Longitudinal Online Research and Imaging System) is a self-hosted web application that provides data- and project-management for neuroimaging research. Prior to 27.0.3 and 28.0.1, the redirect parameter upon login to LORIS was not validating the value of the redirect as being within LORIS, which could be used to trick users into visiting arbitrary URLs if they are given a link with a third party redirect parameter. This vulnerability is fixed in 27.0.3 and 28.0.1.