CVE-2026-103438
Received Received - Intake

Basic XSS in MediaWiki Wikistories 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 Wikistories extension allows Cross-Site Scripting (XSS). This issue affects MediaWiki Wikistories 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-2026-103438
EUVD
EUVD-2026-90210

Affected Vendors & Products

Showing 6 associated CPEs
Vendor Product Version / Range
the_wikimedia_foundation mediawiki_wikistories_extension From 1.43 (inc) to 1.46 (inc)
the_wikimedia_foundation mediawiki_wikistories_extension From 1.45 (inc) to 1.46 (inc)
the_wikimedia_foundation mediawiki_wikistories_extension to 1.46 (inc)
the_wikimedia_foundation mediawiki_wikistories_extension 1.43
the_wikimedia_foundation mediawiki_wikistories_extension 1.45
the_wikimedia_foundation mediawiki_wikistories_extension 1.46

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 basic Cross-Site Scripting (XSS) vulnerability in the Wikimedia Foundation MediaWiki Wikistories extension. It occurs due to improper neutralization of Script-Related HTML tags in a web page, allowing attackers to inject malicious scripts.

Detection Guidance

Check MediaWiki Wikistories extension versions 1.46, 1.45, or 1.43 for vulnerable installations. Inspect web pages for improperly neutralized HTML tags that may indicate XSS attempts.

Impact Analysis

An attacker could exploit this to execute arbitrary JavaScript in a victim's browser when they view a page with the vulnerable extension. This could lead to session hijacking, data theft, or defacement of the wiki.

Compliance Impact

XSS vulnerabilities can violate GDPR by exposing user data or HIPAA by allowing unauthorized access to protected health information if exploited on relevant systems.

Mitigation Strategies

Update the MediaWiki Wikistories extension to a patched version. If updating is not possible, disable the extension until a fix is applied. Monitor web traffic for suspicious scripts or HTML injection attempts.

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