---
cve: "CVE-2026-56857"
severity: "CRITICAL"
cvss: 9.8
epss: "0.5%"
vendor: "Go standard library"
kev: false
exploited: false
published: "2026-10-08 23:17:01"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-11-09T23:50:53+01:00"
---

# CVE-2026-56857

> 9.8 CRITICAL

## Beschreibung

On Windows, when the target of Root.Mkdir or Root.MkdirAll is a junction pointing to an empty location, the operation can create a directory at the junction target even when that target is located outside the root. This only applies to operations where the last path component is a junction (path/to/junction, but not path/junction/target).

## CNA-Record (Kanon, cvelistV5)

- CNA: **Go**
- State: PUBLISHED
- Stand: 2026-10-09 15:36:01

## 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: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-1386** — Insecure Operation on Windows Junction / Mount Point
  The product opens a file or directory, but it does not properly prevent the name from being associated with a junction or mount point to a destination that is outside of the intended control sphere.

## BSI-Hinweise (deutsch)

- [Golang Go: Mehrere Schwachstellen](https://wid.cert-bund.de/portal/wid/sicherheitshinweis/WID-SEC-W-2026-3841) — _BSI-Einstufung: mittel_
  Ein Angreifer kann mehrere Schwachstellen in Golang Go ausnutzen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, um Daten zu manipulieren und um Sicherheitsvorkehrungen zu umgehen.

## Referenzen

- <https://go.dev/cl/847305>
- <https://go.dev/issue/81739>
- <https://groups.google.com/g/golang-announce/c/U2fTuyDJznI>
- <https://pkg.go.dev/vuln/GO-2026-6604>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-56857/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_