{"id":"CVE-2026-39838","aliases":["EUVD-2026-19889","GHSA-9jh3-xqmw-83x6"],"status":"published","title":"ProofreadPage improperly sanitizes multiline styles using Sanitizer::checkCSS","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.\nThe issue has been remediated on the `master` branch, and in the release branches for MediaWiki versions 1.43, 1.44, and 1.45.","severity":{"version":"4.0","score":6.9,"vector":"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00382,"percentile":0.32535,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2026-04-07T19:17:51Z","modified":"2026-07-21T19:10:00Z","products":[{"vendor":"wikimedia foundation","product":"mediawiki - proofreadpage extension"}],"references":[{"url":"https://phabricator.wikimedia.org/T406088"},{"url":"https://gerrit.wikimedia.org/r/q/Idd51e18479b32b7176b43ff74ca1c49d6bdd0628"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39838"},{"url":"https://github.com/advisories/GHSA-9jh3-xqmw-83x6"}],"sources":{"cve":[{"id":"CVE-2026-39838","title":"ProofreadPage improperly sanitizes multiline styles using Sanitizer::checkCSS","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.\nThe issue has been remediated on the `master` branch, and in the release branches for MediaWiki versions 1.43, 1.44, and 1.45.","status":"published","published":"2026-04-07T19:17:51.638Z","modified":"2026-04-08T18:48:41.035Z","cvss":[{"version":"4.0","score":6.9,"vector":"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","level":"medium","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:20:02.662847Z"}],"euvd":[{"id":"EUVD-2026-19889","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.\nThe issue has been remediated on the `master` branch, and in the release branches for MediaWiki versions 1.43, 1.44, and 1.45.","status":"published","published":"2026-04-07T19:17:51Z","modified":"2026-04-08T18:48:41Z","cvss":[{"version":"4.0","score":6.9,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T19:24:31.230458Z"}],"ghsa":[{"id":"GHSA-9jh3-xqmw-83x6","title":"Improper neutralization of input during web page generation ('cross-site scripting')...","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.This issue affects .","status":"published","published":"2026-04-07T21:32:40Z","modified":"2026-04-07T21:32:46Z","cvss":[{"version":"4.0","score":6.9,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:07:11.605224Z"}],"nvd":[{"id":"CVE-2026-39838","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.\nThe issue has been remediated on the `master` branch, and in the release branches for MediaWiki versions 1.43, 1.44, and 1.45.","status":"published","published":"2026-04-07T20:16:33.477Z","modified":"2026-07-21T19:10:00.107Z","cvss":[{"version":"4.0","score":6.9,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:13.535987Z"}]}}