CVE-2026-39933
Received Received - Intake
Cross-Site Scripting in MediaWiki GlobalWatchlist Extension

Publication date: 2026-04-07

Last updated on: 2026-04-08

Assigner: wikimedia-foundation

Description
Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in The Wikimedia Foundation Mediawiki - GlobalWatchlist Extension allows Cross-Site Scripting (XSS). The issue has been remediated on the `master` branch, and in the release branches for MediaWiki versions 1.43, 1.44, and 1.45.
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Meta Information
Published
2026-04-07
Last Modified
2026-04-08
Generated
2026-06-16
AI Q&A
2026-04-08
EPSS Evaluated
2026-06-15
NVD
CVE-2026-39933
EUVD
EUVD-2026-19976
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
the_wikimedia_foundation mediawiki_globalwatchlist_extension *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-79 The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
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Executive Summary

This vulnerability is a Cross-Site Scripting (XSS) issue in the Wikimedia Foundation Mediawiki - GlobalWatchlist Extension. It occurs due to improper neutralization of input during web page generation, which means that malicious scripts can be injected and executed in the context of the affected web pages.

Impact Analysis

The vulnerability can allow attackers to execute arbitrary scripts in the context of users visiting the affected Mediawiki pages. This can lead to theft of sensitive information, session hijacking, defacement of web content, or redirection to malicious sites.

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