---
cve: "CVE-2026-6347"
severity: "HIGH"
cvss: 7.6
epss: "0.3%"
vendor: "Mattermost"
kev: false
exploited: false
published: "2026-05-18 09:16:24"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-11-01T11:47:44+01:00"
---

# CVE-2026-6347

> 7.6 HIGH

## Beschreibung

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to sanitize sensitive configuration fields in the Mattermost Calls plugin which allows an attacker with access to a support packet to obtain TURN server credentials via the plaintext values present in the exported plugin configuration.. Mattermost Advisory ID: MMSA-2026-00605

## CNA-Record (Kanon, cvelistV5)

- CNA: **Mattermost**
- State: PUBLISHED
- Stand: 2026-05-18 14:38:21
- CNA-CVSS: **7.6** (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:L`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **no**
  - Technical Impact: **partial**

## CVSS-Vektor

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

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

## Schwachstellen-Klasse

- **CWE-200** — Exposure of Sensitive Information to an Unauthorized Actor
  The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

## Angriffsmuster (CAPEC)

- [CAPEC-13 — Subverting Environment Variable Values](https://capec.mitre.org/data/definitions/13.html) _(Severity: Very High)_
- [CAPEC-22 — Exploiting Trust in Client](https://capec.mitre.org/data/definitions/22.html) _(Severity: High)_
- [CAPEC-116 — Excavation](https://capec.mitre.org/data/definitions/116.html) _(Severity: Medium)_
- [CAPEC-169 — Footprinting](https://capec.mitre.org/data/definitions/169.html) _(Severity: Very Low)_
- [CAPEC-224 — Fingerprinting](https://capec.mitre.org/data/definitions/224.html) _(Severity: Very Low)_
- [CAPEC-285 — ICMP Echo Request Ping](https://capec.mitre.org/data/definitions/285.html) _(Severity: Low)_
- [CAPEC-287 — TCP SYN Scan](https://capec.mitre.org/data/definitions/287.html) _(Severity: Low)_
- [CAPEC-290 — Enumerate Mail Exchange (MX) Records](https://capec.mitre.org/data/definitions/290.html) _(Severity: Low)_

## ATT&CK-Techniken

- [T1562.003 — Impair Defenses:Impair Command History Logging](https://attack.mitre.org/techniques/T1562/003/)
- [T1574.006 — Hijack Execution Flow:Dynamic Linker Hijacking](https://attack.mitre.org/techniques/T1574/006/)
- [T1574.007 — Hijack Execution Flow:Path Interception by PATH Environment ](https://attack.mitre.org/techniques/T1574/007/)
- [T1217 — Browser Bookmark Discovery](https://attack.mitre.org/techniques/T1217/)
- [T1592 — Gather Victim Host Information](https://attack.mitre.org/techniques/T1592/)
- [T1595 — Active Scanning](https://attack.mitre.org/techniques/T1595/)

## Patch verfügbar (OSV)

- b21ef302025ee100f04f358c16301dc75fea91d9 (Commit)
- 37b08cfe7154241c2c6a8af0fd500e0785bbc900 (Commit)

## Referenzen

- <https://mattermost.com/security-updates>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-6347/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_