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 .

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact Low

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation poc

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Wikimedia Foundation MediaWiki - ProofreadPage Extension unaffected
Version Status Constraints
1.43.7 unaffected —
1.44.4 unaffected —
1.45.2 unaffected —

No data.

No data.

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Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://gerrit.wikimedia.org/r/q/Idd51e18479b32b7176b43ff74ca1c49d6bdd0628 cve-icon cve-icon
https://phabricator.wikimedia.org/T406088 cve-icon cve-icon
History

Tue, 07 Apr 2026 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 07 Apr 2026 20:45:00 +0000

Type Values Removed Values Added
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 .
Title ProofreadPage improperly sanitizes multiline styles using Sanitizer::checkCSS
Weaknesses CWE-79
References
Metrics cvssV4_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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: wikimedia-foundation

Published:

Updated: 2026-04-07T20:42:43.371Z

Reserved: 2026-04-07T18:21:12.573Z

Link: CVE-2026-39838

cve-icon Vulnrichment

Updated: 2026-04-07T20:40:11.397Z

cve-icon NVD

Status : Received

Published: 2026-04-07T20:16:33.477

Modified: 2026-04-07T20:16:33.477

Link: CVE-2026-39838

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses