Wikimedia MediaWiki up to 1.46.0/1.45.4/1.43.9 TemplateSandbox Extension cross site scripting

Summaryinfo

A vulnerability marked as problematic has been reported in Wikimedia MediaWiki up to 1.46.0/1.45.4/1.43.9. Affected by this issue is some unknown functionality of the component TemplateSandbox Extension. The manipulation leads to cross site scripting. This vulnerability is uniquely identified as CVE-2026-100376. The attack is possible to be carried out remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Wikimedia MediaWiki up to 1.46.0/1.45.4/1.43.9 and classified as problematic. This issue affects an unknown code of the component TemplateSandbox Extension. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to 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. Impacted is integrity. The summary by CVE is:

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation Mediawiki - TemplateSandbox Extension allows Cross-Site Scripting (XSS). This issue affects Mediawiki - TemplateSandbox Extension: from * before 1.46.1, 1.45.5, 1.43.10.

The advisory is shared at phabricator.wikimedia.org. The identification of this vulnerability is CVE-2026-100376 since 09/25/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

Upgrading to version 1.46.1, 1.45.5 or 1.43.10 eliminates this vulnerability.

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Productinfo

Type

• Content Management System

Vendor

• Wikimedia

Name

• MediaWiki

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17
• 1.18
• 1.19
• 1.20
• 1.21
• 1.22
• 1.23
• 1.24
• 1.25
• 1.26
• 1.27
• 1.28
• 1.29
• 1.30
• 1.31
• 1.32
• 1.33
• 1.34
• 1.35
• 1.36
• 1.37
• 1.38
• 1.39
• 1.40
• 1.41
• 1.42
• 1.43
• 1.43.0
• 1.43.1
• 1.43.2
• 1.43.3
• 1.43.4
• 1.43.5
• 1.43.6
• 1.43.7
• 1.43.8
• 1.43.9
• 1.44
• 1.45
• 1.45.0
• 1.45.1
• 1.45.2
• 1.45.3
• 1.45.4
• 1.46.0

License

• open-source

CPE 2.3info

• 🔒
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CPE 2.2info

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Entryinfo

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