---
cve: "CVE-2026-100838"
severity: "HIGH"
cvss: 8.6
epss: "0.2%"
vendor: "edgelesssys"
kev: false
exploited: false
published: "2026-09-27 02:17:22"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-10-05T00:14:41+02:00"
---

# CVE-2026-100838

> 8.6 HIGH · 🧪 PoC

## Beschreibung

Contrast is a confidential-computing runtime for Kubernetes. In versions before 1.19.1, the Kata agent policies generated by the Contrast CLI contained a flaw in the CopyFile verification that allowed arbitrary writes to the guest root filesystem. A malicious process on the untrusted host able to connect to the Kata agent VSOCK could issue a series of CopyFile requests to overwrite security-critical files in the guest or trick the workload into disclosing sensitive data, effectively amounting to a full guest takeover. Users unable to upgrade can apply an equivalent rego policy fix passed to 'contrast generate --policy'.

## CNA-Record (Kanon, cvelistV5)

- CNA: **VulnCheck**
- State: PUBLISHED
- Stand: 2026-09-30 16:55:16
- CNA-CVSS: **8.6** (`CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)

## CISA-Anreicherung (vulnrichment/ADP)

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

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- 2a5f2b256d9b0d8517d4653ed4e8bd7d39fb44f3 (Commit)

## Referenzen

- <https://github.com/edgelesssys/contrast/security/advisories/GHSA-rh99-wc69-c255>
- <https://www.vulncheck.com/advisories/contrast-before-1.19.1-copyfile-policy-symlink-subversion>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-100838) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_