Medium severity · published Jul 8, 2025
CVE-2025-53480
CheckUser: Reflected Cross-Site Scripting (XSS) in Special:Investigate (Account information tab) via unsanitized i18n messages
5.4
CVSS
0.2%
EPSS
No
On KEV
Description
The CheckUser extension’s Special:Investigate page has a vulnerability in the Account information tab, where specific internationalized messages are rendered without proper escaping. Attackers can exploit this by appending ?uselang=x-xss to the URL, causing reflected XSS when the UI renders affected message keys.
This issue affects Mediawiki - CheckUser extension: from 1.39.X before 1.39.13, from 1.42.X before 1.42.7, from 1.43.X before 1.43.2.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 10% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MC
Mediawiki - CheckUser extension · Wikimedia Foundation
1.39.x before 1.39.13; 1.42.x before 1.42.7; 1.43.x before 1.43.2 · source: vendor
Affected product
MC
Mediawiki - CheckUser extension
Wikimedia Foundation
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-53480
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-53480
gerrit.wikimedia.org
https://gerrit.wikimedia.org/r/q/I777fc55fef15c3b00df0db268af2b64cb2d6e381
phabricator.wikimedia.org
https://phabricator.wikimedia.org/T394700
More from Mediawiki - CheckUser extension
5.4
CVE-2025-53479
CheckUser: Reflected Cross-Site Scripting (XSS) in Special:CheckUser via unsanitized internationalized message
5.4
CVE-2025-53478
CheckUser: Reflected Cross-Site Scripting (XSS) in Special:Investigate via unsanitized i18n messages