---
id: CVE-2026-100240
title: >-
  Missing Authorization vulnerability in Wikimedia Foundation Mediawiki -
  TemplateSandbox Extension allows Accessing Functionality Not Properly
  Constrained by ACLs.


  This issue affects Mediawiki - TemplateSandbox Extension: from * before 1…
summary: >-
  Missing Authorization vulnerability in Wikimedia Foundation Mediawiki -
  TemplateSandbox Extension allows Accessing Functionality Not Properly
  Constrained by ACLs.


  This issue affects Mediawiki - TemplateSandbox Extension: from * before 1…
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-862
vendor: Wikimedia Foundation
product: Mediawiki - TemplateSandbox Extension
affected:
  - 'mediawiki_-_templatesandbox_extension < 1.46.1, 1.45.5, 1.43.10'
published: '2026-09-29'
updated: '2026-10-01'
sourceUpdated: '2026-10-01T19:17:16.217'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-100240'
references:
  - url: 'https://gerrit.wikimedia.org/r/q/Iaf9f6e2280798af5516197257ddc0264b9ad9fb7'
    label: c4f26cc8-17ff-4c99-b5e2-38fc1793eacc
  - url: 'https://phabricator.wikimedia.org/T407974'
    label: c4f26cc8-17ff-4c99-b5e2-38fc1793eacc
tags:
  - nvd
  - cve.org
epss: 0.00298
epssPercentile: 0.22331
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-10-01T18:07:46.261263Z'
ingestedAt: '2026-09-29T16:39:33.274Z'
---

## Overview

Missing Authorization vulnerability in Wikimedia Foundation Mediawiki - TemplateSandbox Extension allows Accessing Functionality Not Properly Constrained by ACLs.

This issue affects Mediawiki - TemplateSandbox Extension: from * before 1.46.1, 1.45.5, 1.43.10.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.