An issue was discovered in the CheckUser extension for MediaWiki through 1.39.3. Special:CheckUserLog shows usernames that have been hidden.

Stored XSS through a system message when blocking a temporary account that's related to other temporary accounts

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation CheckUser. This vulnerability is associated with program files modules/ext.CheckUser.TempAccounts/components/blockConnectedTempAccountsField.Vue. This issue affects CheckUser: from 1.46.0-rc.0 before 1.46.0.

Suggested investigations: Handle suppressed usernames

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation CheckUser. This issue affects CheckUser: from 1.45.0 before 1.45.2.

Special:Translate tool does not use the correct IP and User-Agent in the CheckUser tool

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in The Wikimedia Foundation Mediawiki - Translate Extension allows Footprinting. Translate extension appears to use jobs to make edits to translation pages. This causes the CheckUser tool to log the wrong IP and User-Agent making these edits un-auditable via the CheckUser tool.This issue affects Mediawiki - Translate Extension: from master before 1.39.

Special:GlobalContributions shows edits on wikis the viewer doesn't have access to

Vulnerability in Wikimedia Foundation CheckUser. This vulnerability is associated with program files src/GlobalContributions/GlobalContributionsPager.Php. This issue affects CheckUser: from * before 1.43.4, 1.44.1.

Wrong E-Mail address composition for usernames with a comma and Umlauts in it like "Döe, Jähn"

Vulnerability in Wikimedia Foundation CheckUser. This vulnerability is associated with program files includes/Mail/UserMailer.Php. This issue affects CheckUser: from * before 1.39.14, 1.43.4, 1.44.1.

Stored XSS through system messages in CheckUser

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation CheckUser. This vulnerability is associated with program files modules/ext.CheckUser.TempAccounts/components/ShowIPButton.Vue, modules/ext.CheckUser.TempAccounts/SpecialBlock.Js. This issue affects CheckUser: from * before 1.44.1.

i18n XSS through Special:CheckUser CheckUser helper

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation CheckUser. This vulnerability is associated with program files modules/ext.CheckUser/checkuser/checkUserHelper/buildUserElement.Js. This issue affects CheckUser: from * before 1.44.1.

Cross-site request forgery (CSRF) vulnerability in the CheckUser extension for MediaWiki allows remote attackers to hijack the authentication of certain users for requests that retrieve sensitive user information via unspecified vectors.

An issue was discovered in the CheckUser extension through 1.34 for MediaWiki. Certain sensitive information within oversighted edit summaries made available via the MediaWiki API was potentially visible to users with various levels of access to this extension. Said users should not have been able to view these oversighted edit summaries via the MediaWiki API.

An issue was discovered in the CheckUser extension through 1.35.0 for MediaWiki. Oversighted edit summaries are still visible in CheckUser results in violation of MediaWiki's permissions model.