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.

Classification

CVE ID: CVE-2025-48934

CVSS Base Severity: MEDIUM

CVSS Base Score: 5.5

CVSS 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

Affected Products

Vendor: denoland

Product: deno

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.05% (probability of being exploited)

EPSS Percentile: 15.65% (scored less or equal to compared to others)

EPSS Date: 2025-06-07 (when was this score calculated)

Stakeholder-Specific Vulnerability Categorization (SSVC)

SSVC Exploitation: poc

SSVC Technical Impact: partial

SSVC Automatable: true

References

https://nvd.nist.gov/vuln/detail/CVE-2025-48934
https://github.com/denoland/deno/security/advisories/GHSA-7w8p-chxq-2789
https://github.com/denoland/deno/pull/29079
https://github.com/denoland/deno/commit/2959e083912420988066a001c2b2d6732a1b562f
https://github.com/denoland/deno/commit/946ccda1aa19a00c478a5e6826b75053b050d753
https://docs.deno.com/api/deno/~/Deno.Env.toObject
https://docs.deno.com/runtime/fundamentals/security/#environment-variables

Timeline