Description
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.
Severity (CVSS)
| Base score | 5.2 |
|---|---|
| Severity | Medium |
| Version | CVSS 3.1 |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
| Provided by | CNA |
Weaknesses
- CWE-863 — CWE-863: Incorrect Authorization
Affected products
| Vendor | Product | Versions |
|---|---|---|
| denoland | deno | < 2.8.1 |
References
- https://github.com/denoland/deno/security/advisories/GHSA-4c8g-jvcx-v4hv (x_refsource_CONFIRM)
Generated from the official CVE List on 24 Jun 2026 09:35 UTC.