JLSEC-2026-110

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Source
https://github.com/JuliaLang/SecurityAdvisories.jl/blob/main/advisories/published/2026/JLSEC-2026-110.md
Import Source
https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-110.json
JSON Data
https://api.osv.dev/v1/vulns/JLSEC-2026-110
Upstream
  • EUVD-2025-16913
Published
2026-04-14T13:10:46.494Z
Modified
2026-07-18T00:01:28.471075125Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N CVSS Calculator
  • 5.5 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X CVSS Calculator
Summary
Deno.env.toObject() ignores the variables listed in --deny-env and returns all environment variables
Details

Summary

The Deno.env.toObject method ignores any variables listed in the --deny-env option of the deno run command. When looking at the documentation of the --deny-env option this might lead to a false impression that variables listed in the option are impossible to read.

PoC

export AWS_SECRET_ACCESS_KEY=my-secret-aws-key

# Works as expected. The program stops with a "NotCapable" error message
echo 'console.log(Deno.env.get("AWS_SECRET_ACCESS_KEY"));' | deno run \
  --allow-env \
  --deny-env=AWS_ACCESS_KEY_ID,AWS_SECRET_ACCESS_KEY -

# All enviroment variables are printed and the --deny-env list is completely disregarded
echo 'console.log(Deno.env.toObject());' | deno run \
  --allow-env \
  --deny-env=AWS_ACCESS_KEY_ID,AWS_SECRET_ACCESS_KEY -

The first example using get exits with the following error:

error: Uncaught (in promise) NotCapable: Requires env access to "AWS_SECRET_ACCESS_KEY", run again with the --allow-env flag
console.log(Deno.env.get("AWS_SECRET_ACCESS_KEY"));
                     ^
    at Object.getEnv [as get] (ext:deno_os/30_os.js:124:10)
    at file:///$deno$stdin.mts:1:22

The second example using toObject prints all environment variables:

[Object: null prototype] {
  ...
  AWS_SECRET_ACCESS_KEY: "my-secret-aws-key",
  ...
}

Impact

Software relying on the combination of both flags to allow access to most environment variables except a few sensitive ones will be vulnerable to malicious code trying to steal secrets using the Deno.env.toObject() method.

Database specific 
{
    "license": "CC-BY-4.0",
    "sources": [
        {
            "modified": "2026-06-17T09:30:30.597Z",
            "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2025-48934",
            "imported": "2026-07-17T21:10:02.858Z",
            "database_specific": {
                "status": "Analyzed"
            },
            "html_url": "https://nvd.nist.gov/vuln/detail/CVE-2025-48934",
            "id": "CVE-2025-48934",
            "published": "2025-06-04T20:15:24.163Z"
        },
        {
            "modified": "2025-07-02T18:31:08Z",
            "url": "https://api.github.com/advisories/GHSA-7w8p-chxq-2789",
            "imported": "2026-07-17T21:10:03.009Z",
            "html_url": "https://github.com/advisories/GHSA-7w8p-chxq-2789",
            "published": "2025-06-04T21:18:18Z",
            "id": "GHSA-7w8p-chxq-2789"
        },
        {
            "modified": "2025-06-04T19:32:14Z",
            "url": "https://euvdservices.enisa.europa.eu/api/enisaid?id=EUVD-2025-16913",
            "imported": "2026-07-17T21:10:06.334Z",
            "html_url": "https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-16913",
            "id": "EUVD-2025-16913",
            "published": "2025-06-04T19:21:17Z"
        }
    ]
}
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
0Unknown introduced version / All previous versions are affected
Fixed
2.6.3+0

Database specific

source 
"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-110.json"