---
cve: "CVE-2026-104721"
severity: "MEDIUM"
cvss: 6.3
epss: ""
vendor: "QOS.CH Sarl"
kev: false
exploited: false
published: "2026-10-02 14:17:10"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-10-03T03:30:14+02:00"
---

# CVE-2026-104721

> 6.3 MEDIUM

## Beschreibung

Path-traversal vulnerability in QOS.CH Sarl Logback-classic on Java (logback-classic module) allows path-traversal vulnerability. More specifically, an 
MDC-based discriminator value flows unsanitized into a nested 
FileAppender path, letting an attacker who influences that MDC value 
(e.g. via an HTTP header)
 create and append log files outside the intended directory. 


This issue affects Logback-classic: from 0.9.14 through 1.6.4.  This vulnerability is similar to CVE-2026-19880 but involves other attack techniques.

## CNA-Record (Kanon, cvelistV5)

- CNA: **NCSC.ch**
- State: PUBLISHED
- Stand: 2026-10-02 13:21:59
- CNA-CVSS: **6.3** (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/S:P/AU:N/RE:M/U:Green`)

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/S:P/AU:N/RE:M/U:Green
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Referenzen

- <https://logback.qos.ch/news.html#1.6.5>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-104721) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_