The WikiCategoryTagCloud extension is vulnerable to reflected XSS via the linkstyle attribute, which is improperly concatenated into inline HTML without escaping. An attacker can inject JavaScript event handlers such as onmouseenter using carefully crafted input via the {{#tag:tagcloud}} parser function, resulting in arbitrary JavaScript execution when a victim hovers over a link in the category cloud.
The vulnerability exists because the linkstyle parameter is only passed through Sanitizer::checkCss() (which does not escape HTML) and is then directly inserted into a style attribute using string concatenation instead of Html::element or Html::openElement.
This issue affects Mediawiki - WikiCategoryTagCloud 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.
Metrics
Affected Vendors & Products
References
History
Mon, 07 Jul 2025 20:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
Metrics |
cvssV3_1
|
Mon, 07 Jul 2025 15:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
Description | The WikiCategoryTagCloud extension is vulnerable to reflected XSS via the linkstyle attribute, which is improperly concatenated into inline HTML without escaping. An attacker can inject JavaScript event handlers such as onmouseenter using carefully crafted input via the {{#tag:tagcloud}} parser function, resulting in arbitrary JavaScript execution when a victim hovers over a link in the category cloud. The vulnerability exists because the linkstyle parameter is only passed through Sanitizer::checkCss() (which does not escape HTML) and is then directly inserted into a style attribute using string concatenation instead of Html::element or Html::openElement. This issue affects Mediawiki - WikiCategoryTagCloud 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. | |
Title | WikiCategoryTagCloud: Reflected Cross-Site Scripting (XSS) via linkstyle attribute in parser function | |
Weaknesses | CWE-79 | |
References |
|

Status: PUBLISHED
Assigner: wikimedia-foundation
Published: 2025-07-07T15:07:44.875Z
Updated: 2025-07-07T19:15:02.740Z
Reserved: 2025-06-30T15:20:44.462Z
Link: CVE-2025-53486

Updated: 2025-07-07T19:13:14.209Z

Status : Received
Published: 2025-07-07T15:15:27.947
Modified: 2025-07-07T20:15:27.460
Link: CVE-2025-53486

No data.