CVE-2025-48934CWE-201

Deno.env.toObject() ignores the variables listed in --deny-env and returns all environment variables

Medium · published June 4, 2025

CVSS v4.0
5.5
EPSS
0%
Percentile
35.8
In the wild
Unconfirmed
What it is

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to versions 2.1.13 and 2.2.13, 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. 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. Versions 2.1.13 and 2.2.13 contains a patch.

The record
Technical detail
CVSS v4.0
5.5 · MEDIUM
Vector
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
EPSS
0.00426 · 35.8th percentile
Weakness
CWE-201 · Insertion of Sensitive Information Into Sent Data
Published
2025-06-04T19:21Z
EPSS history
Timeline
  • 04 JUN 19:21Z
    Deno.env.toObject() ignores the variables listed in --deny-env and returns all environment variables
    cvelistv5