---
cve: "CVE-2026-49983"
severity: "MEDIUM"
cvss: 5.2
epss: "10%"
vendor: "denoland"
kev: false
exploited: false
published: "2026-06-23 18:18:04"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-12T16:38:33+02:00"
---

# CVE-2026-49983

> 5.2 MEDIUM · 🧪 PoC

## Beschreibung

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.1, environment access is gated by the env permission. You can deny it with --deny-env, or restrict it to a specific allowlist with --allow-env=FOO,BAR. The expectation is that a program running without env permission cannot change process.env. process.loadEnvFile() (the Node-compatible API for loading variables from a .env file) does not honor this. It only checks that the program has read permission for the dotenv file, then writes every key in that file into the process environment — even when env access is denied. In effect, --allow-read plus a writable or attacker-controlled .env file is enough to defeat --deny-env. This vulnerability is fixed in 2.8.1.

## CVSS-Vektor

```
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Verändert | bad |
| C Vertraulichkeit | Gering | warn |
| I Integrität | Gering | warn |
| A Verfügbarkeit | Keine | good |

## Patch verfügbar (OSV)

- 3e2030bc01776ce6b4ca355b1e78c4cb98c82dca (Commit)

## Referenzen

- <https://github.com/denoland/deno/security/advisories/GHSA-4c8g-jvcx-v4hv>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-49983) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_