CVE-2026-103443
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XSS in MediaWiki Collection Book 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 Collection (Book) extension allows XSS Targeting Non-Script Elements. This issue affects MediaWiki Collection (Book) extension: 1.46, 1.45, and 1.43.

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Meta Information

Published
2026-09-30
Last Modified
2026-09-30
Generated
2026-09-30
AI Q&A
2026-09-30
EPSS Evaluated
N/A
NVD
CVE-2026-103443
EUVD
EUVD-2026-90079

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
the_wikimedia_foundation mediawiki_collection 1.46
the_wikimedia_foundation mediawiki_collection 1.45
the_wikimedia_foundation mediawiki_collection 1.43

Helpful Resources

Exploitability

CWE
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KEV
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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

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Executive Summary

This is a stored cross-site scripting (XSS) vulnerability in the MediaWiki Collection extension's API. It allows attackers to inject malicious JavaScript URLs into the user's session without authentication or CSRF tokens. When a victim accesses Special:Book and clicks a generated link, the JavaScript executes in the wiki's origin, running arbitrary code with the victim's browser privileges.

Detection Guidance

Check MediaWiki Collection extension versions 1.46, 1.45, and 1.43 for the vulnerability. Inspect API calls to Special:Book for unsanitized javascript: URLs stored in user sessions. Look for unexpected JavaScript execution when accessing generated links.

Impact Analysis

An attacker could steal session cookies, perform actions on your behalf, or redirect you to malicious sites. Since it requires user interaction, victims must click a specially crafted link. No special permissions or accounts are needed for the attacker to exploit this.

Compliance Impact

This XSS vulnerability could lead to unauthorized data access or modification, violating GDPR's integrity and confidentiality principles. For HIPAA, it may expose protected health information if exploited in a healthcare wiki. Compliance risks include data breaches and lack of adequate security controls.

Mitigation Strategies

Update MediaWiki Collection extension to the patched versions (REL1_43, REL1_45, REL1_46, or master). Apply URL sanitization before rendering to block javascript: schemes. Review and restrict API access to prevent unauthorized session modifications.

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