---
cve: "CVE-2026-100240"
severity: "CRITICAL"
cvss: 9.1
epss: "0.3%"
vendor: "Wikimedia Foundation"
kev: false
exploited: false
published: "2026-09-29 17:17:01"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-10-28T18:15:40+01:00"
---

# CVE-2026-100240

> 9.1 CRITICAL

## Beschreibung

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.

## CNA-Record (Kanon, cvelistV5)

- CNA: **wikimedia-foundation**
- State: PUBLISHED
- Stand: 2026-10-01 18:07:53

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **yes**
  - Technical Impact: **total**

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Keine | good |

## Schwachstellen-Klasse

- **CWE-862** — Missing Authorization
  The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

## Angriffsmuster (CAPEC)

- [CAPEC-665 — Exploitation of Thunderbolt Protection Flaws](https://capec.mitre.org/data/definitions/665.html) _(Severity: Very High)_

## ATT&CK-Techniken

- [T1211 — Exploitation for Defensive Evasion](https://attack.mitre.org/techniques/T1211/)
- [T1542.002 — Pre-OS Boot: Component Firmware](https://attack.mitre.org/techniques/T1542/002/)
- [T1556 — Modify Authentication Process](https://attack.mitre.org/techniques/T1556/)

## Referenzen

- <https://phabricator.wikimedia.org/T407974>
- <https://gerrit.wikimedia.org/r/q/Iaf9f6e2280798af5516197257ddc0264b9ad9fb7>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-100240/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_