CVE-2025-53479

MEDIUM

Mediawiki - CheckUser <1.42.7-1.43.2 - XSS

Title source: llm

Description

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.

References (2)

Core 2

Core References

Issue Tracking

https://phabricator.wikimedia.org/T394693

Various Sources

https://gerrit.wikimedia.org/r/q/I159e14543912cb3bc7f4a00c3090c0285b154786

Scores

CVSS v3 5.4

EPSS 0.0017

EPSS Percentile 6.7%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment

Exploitation poc

Automatable no

Technical Impact partial

Details

CWE

CWE-79

Status published

Products (2)

Wikimedia Foundation/Mediawiki - CheckUser extension 1.42.x - 1.42.7

Wikimedia Foundation/Mediawiki - CheckUser extension 1.43.x - 1.43.2

Published Jul 08, 2025

Tracked Since Feb 18, 2026