Medium severity · published Feb 3, 2026
CVE-2025-61651
i18n XSS through Special:CheckUser CheckUser helper
6.1
CVSS
0.2%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 12% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CH
CheckUser · Wikimedia Foundation
before 1.44.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-61651
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-61651
Permissions Required
https://phabricator.wikimedia.org/T403408
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