In Mahara before 20.10.5, 21.04.4, 21.10.2, and 22.04.0, a site using Isolated Institutions is vulnerable if more than ten groups are used. They are all shown from page 2 of the group results list (rather than only being shown for the institution that the viewer is a member of).

Mahara before 20.10.5, 21.04.4, 21.10.2, and 22.04.0 allows stored XSS when a particular Cascading Style Sheets (CSS) class for embedly is used, and JavaScript code is constructed to perform an action.

Mahara before 20.10.5, 21.04.4, 21.10.2, and 22.04.0 is vulnerable to Cross Site Request Forgery (CSRF) because randomly generated tokens are too easily guessable.

In Mahara before 20.04.5, 20.10.3, 21.04.2, and 21.10.0, the account associated with a web services token is vulnerable to being exploited and logged into, resulting in information disclosure (at a minimum) and often escalation of privileges.

In Mahara before 20.04.5, 20.10.3, 21.04.2, and 21.10.0, exported CSV files could contain characters that a spreadsheet program could interpret as a command, leading to execution of a malicious string locally on a device, aka CSV injection.

Mahara 16.10 before 16.10.9 and 17.04 before 17.04.7 and 17.10 before 17.10.4 are vulnerable to bad input when TinyMCE is bypassed by POST packages. Therefore, Mahara should not rely on TinyMCE's code stripping alone but also clean input on the server / PHP side as one can create own packets of POST data containing bad content with which to hit the server.

Mahara 16.10 before 16.10.7, 17.04 before 17.04.5, and 17.10 before 17.10.2 are vulnerable to being forced, via a man-in-the-middle attack, to interact with Mahara on the HTTP protocol rather than HTTPS even when an SSL certificate is present.

Mahara 16.10 before 16.10.7 and 17.04 before 17.04.5 and 17.10 before 17.10.2 have a Cross Site Scripting (XSS) vulnerability when a user enters invalid UTF-8 characters. These are now going to be discarded in Mahara along with NULL characters and invalid Unicode characters. Mahara will also avoid direct $_GET and $_POST usage where possible, and instead use param_exists() and the correct param_*() function to fetch the expected value.

An issue was discovered in Mahara before 18.10.0. It mishandled user requests that could discontinue a user's ability to maintain their own account (changing username, changing primary email address, deleting account). The correct behavior was to either prompt them for their password and/or send a warning to their primary email address.