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CVE-2026-100240

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.

Scores

9.1
CVSS 9.1 out of 10, critical severity.
0.3%
EPSS 0.3% chance of exploitation in the next 30 days.

The facts

Published
29 September 2026
Last changed
1 October 2026
NVD status
Awaiting Analysis
Severity
Critical, CVSS 9.1 out of 10 (version 3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness
Known exploited
Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
EPSS
0.3% chance of exploitation activity in the next 30 days (percentile 21).

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References