---
cve: "CVE-2026-31271"
severity: "CRITICAL"
cvss: 9.8
epss: "0.7%"
vendor: "n/a"
kev: false
exploited: false
published: "2026-04-07 18:16:41"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-11-07T10:37:45+01:00"
---

# CVE-2026-31271

> 9.8 CRITICAL · 🧪 PoC

## Beschreibung

megagao production_ssm v1.0 contains an authorization bypass vulnerability in the user addition functionality. The insert() method in UserController.java lacks authentication checks, allowing unauthenticated attackers to create super administrator accounts by directly accessing the /user/insert endpoint. This leads to complete system compromise.

## CNA-Record (Kanon, cvelistV5)

- CNA: **mitre**
- State: PUBLISHED
- Stand: 2026-04-09 14:01:47

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **poc**
  - 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:H
```

| 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 | Hoch | bad |

## Schwachstellen-Klasse

- **CWE-288** — Authentication Bypass Using an Alternate Path or Channel
  The product requires authentication, but the product has an alternate path or channel that does not require authentication.

## Angriffsmuster (CAPEC)

- [CAPEC-127 — Directory Indexing](https://capec.mitre.org/data/definitions/127.html) _(Severity: Medium)_
- [CAPEC-665 — Exploitation of Thunderbolt Protection Flaws](https://capec.mitre.org/data/definitions/665.html) _(Severity: Very High)_

## ATT&CK-Techniken

- [T1083 — File and Directory Discovery](https://attack.mitre.org/techniques/T1083/)
- [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://github.com/clockw1se0v0/Vul/blob/main/production_ssm/Unauthorized.md>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-31271/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_