If a malformed data is input to the affected product, a CSV file downloaded from the affected product may contain such malformed data. When a victim user download and open such a CSV file, the embedded code may be executed in the user's environment. Note that Movable Type 7 series and 8.4 series, which are End-of-Life (EOL), are affected by the vulnerability as well.

URL redirection to untrusted site ('Open Redirect') issue exists in Movable Type. If this vulnerability is exploited, an invalid parameter may be inserted into the password reset page, which may lead to redirection to an arbitrary URL.

Movable Type contains a reflected cross-site scripting vulnerability in the user information edit page. When Multi-Factor authentication plugin is enabled and a user accesses a crafted page while logged in to the affected product, an arbitrary script may be executed on the web browser of the user.

Movable Type contains a stored cross-site scripting vulnerability in the HTML edit mode of MT Block Editor. It is exploitable when TinyMCE6 is used as a rich text editor and an arbitrary script may be executed on a logged-in user's web browser.