CVE-2026-39838

ProofreadPage improperly sanitizes multiline styles using Sanitizer::checkCSS

State: Published
Severity: 6.9 Medium
Published: Apr 7, 2026
Updated: Apr 8, 2026
Reserved: Apr 7, 2026

Description

Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Wikimedia Foundation MediaWiki - ProofreadPage Extension allows XSS Targeting Non-Script Elements. The issue has been remediated on the `master` branch, and in the release branches for MediaWiki versions 1.43, 1.44, and 1.45.

Scores

CVSS	Score	Vector	Source
4.0	6.9 Medium	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:N/SA:N	wikimedia-foundation

Weaknesses

CWE-79 Improper neutralization of input during web page generation ('cross-site scripting')

Affected Products

Product	Versions
MediaWiki - ProofreadPage ExtensionWikimedia Foundation	before 1.43Affected 1.43Not affected 1.44Not affected 1.45Not affected

References

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