What’s Vulnerable › Vulnerabilities

CVE-2026-39933: Multiple XSS vulnerabilities in GlobalWatchlist

• Severity: medium (CVSS 6.9 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-07 · updated 2026-07-21
• Weakness: CWE-79

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.

Affected products

• The Wikimedia Foundation Mediawiki - GlobalWatchlist Extension: before 1.43 — fixed in 1.43

How to fix

Upgrade to a fixed version: The Wikimedia Foundation Mediawiki - GlobalWatchlist Extension 1.43. Check the vendor advisory for mitigations.

References

• https://gerrit.wikimedia.org/r/q/I1fc7b7e1d234b0aaf9f7d782a65da1451577587e
• https://phabricator.wikimedia.org/T418179

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