Vulnerability · Published Jun 4, 2025 · Assigned by GitHub_M

CVE-2025-48934Deno.env.toObject() ignores the variables listed in --deny-env and returns all environment variables

Medium 5.5

In plain English

A medium-severity security flaw in deno from denoland. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities).

Severity (CVSS 4.0)5.5Medium

Exploit odds (30 days)0.4%top 61.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
denoland	deno	< 2.1.13>= 2.2.0, < 2.2.13

Weakness: CWE-201 · 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

References

https://github.com/denoland/deno/security/advisories/GHSA-7w8p-chxq-2789 x_refsource_CONFIRM
https://github.com/denoland/deno/pull/29079 x_refsource_MISC
https://github.com/denoland/deno/commit/2959e083912420988066a001c2b2d6732a1b562f x_refsource_MISC
https://github.com/denoland/deno/commit/946ccda1aa19a00c478a5e6826b75053b050d753 x_refsource_MISC
https://docs.deno.com/api/deno/~/Deno.Env.toObject x_refsource_MISC
https://docs.deno.com/runtime/fundamentals/security/#environment-variables x_refsource_MISC