CVE-2026-100380

Received Received - Intake

Stored XSS in MediaWiki Wikibase 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 - Wikibase Extension allows Cross-Site Scripting (XSS). This issue affects Mediawiki - Wikibase Extension: from * before 1.46.1, 1.45.5, 1.43.10.

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-2026-100380

Affected Vendors & Products

Vendor	Product	Version / Range
wikimedia_foundation	mediawiki_wikibase_extension	From 1.43.10 (inc) to 1.46.1 (exc)
wikimedia_foundation	mediawiki_wikibase_extension	1.45.5
wikimedia_foundation	mediawiki_wikibase_extension	1.43.10

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 Wikibase Extension. It allows attackers to inject malicious scripts into web pages viewed by other users due to improper neutralization of input during web page generation.

Detection Guidance

This vulnerability is specific to the MediaWiki Wikibase Extension and requires checking the version of the extension installed. No direct network or system commands are provided in the context to detect this XSS vulnerability. Review the extension version against the affected versions (before 1.46.1, 1.45.5, 1.43.10) and inspect web application logs for suspicious input patterns.

Impact Analysis

An attacker could exploit this to steal user sessions, deface websites, or perform actions on behalf of users. Users viewing affected pages may have their data compromised or be redirected to malicious sites.

Compliance Impact

This XSS vulnerability could lead to unauthorized data access or modification, violating GDPR's data protection requirements and HIPAA's safeguards for protected health information. Non-compliance risks fines and legal consequences.

Mitigation Strategies

Update the Mediawiki Wikibase Extension to version 1.46.1, 1.45.5, or 1.43.10 or later to address the XSS vulnerability.

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