CVE-2025-53479
CheckUser: Reflected Cross-Site Scripting (XSS) in Special:CheckUser via unsanitized internationalized message
Vexday Risk Score
13Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS 5.4EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —
Lifecycle
08 Jul 2025Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
The CheckUser extension’s Special:CheckUser interface is vulnerable to reflected XSS via the rev-deleted-user message. This message is rendered without proper escaping, making it possible to inject JavaScript through the uselang=x-xss language override mechanism.
This issue affects Mediawiki - CheckUser extension: from 1.42.X before 1.42.7, from 1.43.X before 1.43.2.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Affected products
Wikimedia Foundation · Mediawiki - CheckUser extensionWant to know if your infrastructure is exposed to this?
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