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GHSA-4c8g-jvcx-v4hv

MediumCVSS 5.2 / 10
Published Jun 16, 2026·Last modified Jun 16, 2026
Affected Components(0)

No affected components available

Description

Summary

In Deno, 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.

Am I affected?

You are potentially affected if all of the following are true:

  1. You run Deno v2.3.0 or newer.
  2. Your program (or any dependency it imports) calls process.loadEnvFile() from node:process.
  3. You rely on Deno's permission model — specifically --deny-env, an --allow-env=… allowlist, or running without granting env — as a security boundary.
  4. The .env path passed to loadEnvFile() can be controlled or modified by a less-trusted party (untrusted input, user-writable directory, third-party dependency, etc.) and is covered by your --allow-read grant.

If your program does not use process.loadEnvFile() at all, or if it already grants full env access, this advisory does not change your risk.

Risk Scores
Base Score
5.2

The vulnerability requires local access to the device to be exploited. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. No user interaction is needed for the attacker to exploit this vulnerability. The vulnerability can affect other systems as well, not just the initial system. There is a low impact on the confidentiality of the information. There is a low impact on the integrity of the data.

Threat Intelligence
4.8

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
0.10%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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Medium severity
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