XSS in Wikimedia Foundation MediaWiki - Approvedrevs Extension

CVE-2025-53487

The ApprovedRevs extension for MediaWiki is vulnerable to stored XSS in multiple locations where system messages are inserted into raw HTML without proper escaping. Attackers can exploit this by injecting JavaScript payloads via the uselang=x-xss language override, which causes crafted message keys to be rendered unescaped. This issue affects Mediawiki - ApprovedRevs 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.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (7.1th 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

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-53487?
CVE-2025-53487 is a medium-severity vulnerability in Wikimedia Foundation MediaWiki - Approvedrevs Extension, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2025-07-07.
How severe is CVE-2025-53487?
Medium severity. CVSS v3 base score is 5.4 out of 10.