CVE-2026-39838 — ProofreadPage improperly sanitizes multiline styles using Sanitizer::checkCSS
Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Wikimedia Foundation MediaWiki - ProofreadPage Extension allows XSS Targeti…
Published: 2026-04-07 · CVSS: 6.9 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7