---
cve: "CVE-2026-100864"
severity: "HIGH"
cvss: 8.7
epss: "0.7%"
vendor: "heymrun"
kev: false
exploited: false
published: "2026-09-27 02:17:26"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-29T09:08:31+02:00"
---

# CVE-2026-100864

> 8.7 HIGH · 🧪 PoC

## Beschreibung

heym before 0.0.91 contains a sandbox escape vulnerability in the expression engine's DotList map/filter and fallback resolver that allows authenticated users to execute arbitrary Python code. Attackers can craft workflow expressions using dunder attribute access through item expressions or the fallback resolver to access os.system and execute commands as the backend process.

## CNA-Record (Kanon, cvelistV5)

- CNA: **VulnCheck**
- State: PUBLISHED
- Stand: 2026-09-28 16:04:18
- CNA-CVSS: **8.7** (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **poc**
  - Automatable: **no**
  - Technical Impact: **total**

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- 1267b7b6a02f88eb447a5d09057296c4fac54c67 (Commit)

## Referenzen

- <https://github.com/heymrun/heym/security/advisories/GHSA-87x2-9jwx-7gh4>
- <https://www.vulncheck.com/advisories/heym-before-0.0.91-remote-code-execution-via-expression-engine>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-100864) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_