CVE-2026-100383: Stored i18n XSS in WikiLambda's VisualEditor integration

Severity: medium (CVSS 4.8 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: 2026-09-25 · updated 2026-09-28
Weakness: CWE-79

Description

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation Mediawiki - WikiLambda Extension allows Cross-Site Scripting (XSS). This issue affects Mediawiki - WikiLambda Extension: 1.47.0-alpha. The issue has been remediated on the `master` branch.

Affected products

Wikimedia Foundation Mediawiki - WikiLambda Extension: 1.47.0-alpha

References

https://gerrit.wikimedia.org/r/c/mediawiki/extensions/WikiLambda/+/1326391
https://phabricator.wikimedia.org/T434967

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