XSS in Wikimedia Foundation MediaWiki - Proofreadpage Extension

CVE-2026-39838

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.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.004 (32.9th percentile) — read the EPSS interpretation.

Affected products

Weakness classification (CWE)

References