CVE-2025-61651 PUBLISHED

i18n XSS through Special:CheckUser CheckUser helper

Assigner: wikimedia-foundation
Reserved: 29.09.2025 Published: 03.02.2026 Updated: 03.02.2026

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.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N/E:U
CVSS Score: 0

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	High
User Interaction	None

CVSS 4.0

Product Status

Vendor	Wikimedia Foundation
Product	CheckUser
Versions	Default: unaffected affected from * to 1.44.1 (excl.)

References

https://phabricator.wikimedia.org/T403408

Problem Types

CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') CWE