CVE-2026-100383

Received Received - Intake

Stored XSS in MediaWiki WikiLambda Extension

Publication date: 2026-09-25

Last updated on: 2026-09-25

Assigner: wikimedia-foundation

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-25

Last Modified

2026-09-25

Generated

2026-09-26

AI Q&A

2026-09-26

EPSS Evaluated

N/A

NVD

CVE-2026-100383

Affected Vendors & Products

Vendor	Product	Version / Range
wikimedia	mediawiki_wikilambda_extension	1.47.0-alpha

Helpful Resources

Exploitability

CWE

KEV

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.

Attack-Flow Graph

Executive Summary

This is a Cross-Site Scripting (XSS) vulnerability in the Wikimedia Foundation MediaWiki WikiLambda Extension version 1.47.0-alpha. It allows attackers to inject malicious scripts into web pages viewed by other users due to improper neutralization of user input during web page generation.

Impact Analysis

An attacker could exploit this to steal cookies, session tokens, or other sensitive data from users of the affected WikiLambda Extension. It may also allow unauthorized actions to be performed on behalf of users or defacement of web pages.

Compliance Impact

This XSS vulnerability could lead to unauthorized access to personal data, violating GDPR's data protection principles. For HIPAA, it may risk exposure of protected health information if exploited on healthcare-related wikis.

Mitigation Strategies

Update the Mediawiki WikiLambda Extension to the latest version on the master branch to remediate the vulnerability.

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