The ScratchLogin extension through 1.1 for MediaWiki does not escape verification failure messages, which allows users with administrator privileges to perform cross-site scripting (XSS).

A Cross-Site Request Forgery (CSRF) in RequirementsBypassPage.php of Scratch Wiki scratch-confirmaccount-v3 allows attackers to modify account request requirement bypasses.

HTML Injection in ScratchSig

The ScratchSig extension for MediaWiki before version 1.0.1 allows stored Cross-Site Scripting. Using <script> tag inside <scratchsig> tag, attackers with edit permission can execute scripts on visitors' browser. With MediaWiki JavaScript API, this can potentially lead to privilege escalation and/or account takeover. This has been patched in release 1.0.1. This has already been deployed to all Scratch Wikis. No workarounds exist other than disabling the extension completely.

Authentication Bypass in Scratch Login (mediawiki-scratch-login)

in Scratch Login (MediaWiki extension) before version 1.1, any account can be logged into by using the same username with leading, trailing, or repeated underscore(s), since those are treated as whitespace and trimmed by MediaWiki. This affects all users on any wiki using this extension. Since version 1.1, comments by users whose usernames would be trimmed on MediaWiki are ignored when searching for the verification code.