VulnerabilityDeferred

CVE-2025-53486

The WikiCategoryTagCloud extension is vulnerable to reflected XSS via the linkstyle attribute, which is improperly concatenated into inline HTML without escaping.

MEDIUM 5.4EPSS 0.25%

Does this matter?

Lower severity and a low EPSS score (0.25%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1: 5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS: 0.25% probability · 16th percentile
CISA KEV: Not listed
Weakness: CWE-79
Source: c4f26cc8-17ff-4c99-b5e2-38fc1793eacc

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.