---
cve: "CVE-2026-27199"
severity: "MEDIUM"
cvss: 6.3
epss: "56%"
vendor: "pallets"
kev: false
exploited: false
published: "2026-02-21 06:17:00"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-06T04:24:50+02:00"
---

# CVE-2026-27199

> 6.3 MEDIUM · 🧪 PoC

## Beschreibung

Werkzeug is a comprehensive WSGI web application library. Versions 3.1.5 and below, the safe_join function allows Windows device names as filenames if preceded by other path segments. This was previously reported as GHSA-hgf8-39gv-g3f2, but the added filtering failed to account for the fact that safe_join accepts paths with multiple segments, such as example/NUL. The function send_from_directory uses safe_join to safely serve files at user-specified paths under a directory. If the application is running on Windows, and the requested path ends with a special device name, the file will be opened successfully, but reading will hang indefinitely. This issue has been fixed in version 3.1.6.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
```

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

## Patch verfügbar (OSV)

- 04da1b5221b7a7b57e82246e4b5741d37a6b2e56 (Commit)
- f407712fdc60a09c2b3f4fe7db557703e5d9338d (Commit)

## Referenzen

- <https://github.com/pallets/werkzeug/security/advisories/GHSA-29vq-49wr-vm6x>
- <https://github.com/pallets/werkzeug/commit/f407712fdc60a09c2b3f4fe7db557703e5d9338d>
- <https://github.com/pallets/werkzeug/releases/tag/3.1.6>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-27199) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_