What is CVE-2025-53478?

CVE-2025-53478 is a medium-severity vulnerability in Wikimedia Foundation Mediawiki - Checkuser Extension, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2025-07-07.

How severe is CVE-2025-53478?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in Wikimedia Foundation Mediawiki - Checkuser Extension

CVE-2025-53478

The CheckUser extension’s Special:Investigate interface is vulnerable to reflected XSS due to improper escaping of certain internationalized system messages rendered on the “IPs and User agents” tab. This issue affects Mediawiki - Chec…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (6.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: 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 Extension — versions 1.39.x, 1.42.x, 1.43.x

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

Frequently asked questions

What is CVE-2025-53478?: CVE-2025-53478 is a medium-severity vulnerability in Wikimedia Foundation Mediawiki - Checkuser Extension, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2025-07-07.
How severe is CVE-2025-53478?: Medium severity. CVSS v3 base score is 5.4 out of 10.