CVE-2026-103584

Received Received - Intake

Stored XSS in MediaWiki CommonsMetadata Extension

Publication date: 2026-09-30

Last updated on: 2026-09-30

Assigner: wikimedia-foundation

Description

Improper neutralization of Script-Related HTML tags in a web page (basic XSS) vulnerability in The Wikimedia Foundation MediaWiki CommonsMetadata extension allows Cross-Site Scripting (XSS). This issue affects MediaWiki CommonsMetadata extension: 1.46, 1.45, and 1.43.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-09-30

Last Modified

2026-09-30

Generated

2026-10-01

AI Q&A

2026-10-01

EPSS Evaluated

N/A

NVD

CVE-2026-103584

EUVD

EUVD-2026-90430

Affected Vendors & Products

Vendor	Product	Version / Range
the_wikimedia_foundation	mediawiki_commonsmetadata_extension	1.46
the_wikimedia_foundation	mediawiki_commonsmetadata_extension	1.45
the_wikimedia_foundation	mediawiki_commonsmetadata_extension	1.43

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-80	The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.

Attack-Flow Graph

Executive Summary

This is a basic Cross-Site Scripting (XSS) vulnerability caused by improper neutralization of Script-Related HTML tags in the Wikimedia Foundation MediaWiki CommonsMetadata extension. It allows attackers to inject malicious scripts into web pages.

Detection Guidance

This vulnerability involves improper neutralization of Script-Related HTML tags in MediaWiki CommonsMetadata extension. Detection requires checking for XSS payloads in user inputs or rendered pages. Inspect MediaWiki logs for suspicious script tags or unusual HTML rendering. Use tools like OWASP ZAP or Burp Suite to scan for XSS vulnerabilities in the extension.

Impact Analysis

An attacker could exploit this to execute arbitrary JavaScript in a victim's browser when they visit a page using the vulnerable extension. This could lead to theft of session cookies, account takeover, or defacement of the wiki page.

Compliance Impact

This XSS vulnerability could lead to unauthorized access to user data, violating GDPR's data protection principles and HIPAA's security requirements for protected health information. It may result in non-compliance and potential legal consequences.

Mitigation Strategies

Update the MediaWiki CommonsMetadata extension to a patched version if available. If no patch exists, consider disabling the extension until a fix is released. Review web application firewall rules to block XSS payloads.

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