CVE-2026-49983

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 v3 5.2 MEDIUM

5.2^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.0 / Impact : 2.7

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/denoland/deno/security/advisories/GHSA-4c8g-jvcx-v4hv	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:deno:deno:*:*:*:*:*:*:*:*

History

29 Jun 2026, 13:35

Type	Values Removed	Values Added
First Time		Deno Deno deno
References	~~() https://github.com/denoland/deno/security/advisories/GHSA-4c8g-jvcx-v4hv -~~	() https://github.com/denoland/deno/security/advisories/GHSA-4c8g-jvcx-v4hv - Vendor Advisory
CPE		cpe:2.3:a:deno:deno::::::::

23 Jun 2026, 18:18

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-06-23 18:18

Updated : 2026-06-29 13:35

NVD link : CVE-2026-49983

Mitre link : CVE-2026-49983

CVE.ORG link : CVE-2026-49983

JSON object : View

Products Affected

deno

deno

CWE

CWE-863

Incorrect Authorization

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