JLSEC-2026-1166

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Source
https://github.com/JuliaLang/SecurityAdvisories.jl/blob/main/advisories/published/2026/JLSEC-2026-1166.md
Import Source
https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-1166.json
JSON Data
https://api.osv.dev/v1/vulns/JLSEC-2026-1166
Upstream
  • EUVD-2026-38543
Published
2026-08-05T18:20:40.259Z
Modified
2026-08-05T18:37:00.205985932Z
Severity
  • 5.2 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N CVSS Calculator
Summary
Deno: process.loadEnvFile() bypasses env permission checks and mutates process.env with only read access
Details

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.

Database specific 
{
    "sources": [
        {
            "imported": "2026-08-05T06:30:31.300Z",
            "id": "CVE-2026-49983",
            "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-49983",
            "html_url": "https://nvd.nist.gov/vuln/detail/CVE-2026-49983",
            "modified": "2026-06-29T13:35:34.613Z",
            "database_specific": {
                "status": "Analyzed"
            },
            "published": "2026-06-23T18:18:04.190Z"
        },
        {
            "id": "GHSA-4c8g-jvcx-v4hv",
            "url": "https://api.github.com/advisories/GHSA-4c8g-jvcx-v4hv",
            "html_url": "https://github.com/advisories/GHSA-4c8g-jvcx-v4hv",
            "modified": "2026-07-20T21:01:25Z",
            "imported": "2026-08-05T06:30:33.882Z",
            "published": "2026-06-16T19:04:57Z"
        },
        {
            "id": "EUVD-2026-38543",
            "url": "https://euvdservices.enisa.europa.eu/api/enisaid?id=EUVD-2026-38543",
            "html_url": "https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-38543",
            "modified": "2026-06-23T17:54:51Z",
            "imported": "2026-08-05T06:30:31.318Z",
            "published": "2026-06-23T17:16:17Z"
        }
    ],
    "license": "CC-BY-4.0"
}
References
Credits

Affected packages

Julia / Deno_jll

Package

Name
Deno_jll
Purl
pkg:julia/Deno_jll?uuid=04572ae6-984a-583e-9378-9577a1c2574d

Affected ranges

Type
SEMVER
Events
Introduced
2.6.3+0
Fixed
2.8.1+0

Database specific

source 
"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-1166.json"