CVE-2026-58034: vulnerability in Wikimedia Foundation CheckUser
Stored XSS through a system message when blocking a temporary account that's related to other temporary accounts
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 0epss 0.3%
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.
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:A/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N
Affected products
Wikimedia Foundation · CheckUserRelated CVEs — Wikimedia Foundation CheckUser
In the same product, most dangerous first.
CVE-2025-61649LOWUserInfoCard: Check that performing user has permission to view log entries for number of past blocksEPSS 0.4%CVE-2025-67478NONEWrong E-Mail address composition for usernames with a comma and Umlauts in it like "Döe, Jähn"EPSS 0.3%CVE-2025-61647LOWUserInfoCard: Don't allow access to information about users who are suppressed if you don't have suppressor rightsEPSS 0.3%CVE-2025-61650LOWUserInfoCard is vulnerable to message key stored XSSEPSS 0.3%CVE-2026-34090MEDIUMSuggested investigations: Handle suppressed usernamesEPSS 0.3%CVE-2025-61658LOWSpecial:GlobalContributions shows edits on wikis the viewer doesn't have access toEPSS 0.3%