Shescape has potential environment variable exposure on Windows with CMD
Impact
This impact users of Shescape on Windows that explicitly configure shell: 'cmd.exe' or shell: true using any of quote/quoteAll/escape/escapeAll.
An attacker may be able to get read-only access to environment variables. Example:
import * as cp from "node:child_process";
import { Shescape } from "shescape";
// 1. Prerequisites
const shescape = new Shescape({
shell: "cmd.exe",
// Or
shell: true, // Only if the default shell is CMD
});
// 2. Payload
const payload = '"%PATH%';
// 3. Usage
let escapedPayload;
escapedPayload = shescape.quote(payload);
// Or
escapedPayload = shescape.quoteAll([payload]);
// Or
escapedPayload = shescape.escape(payload);
// Or
escapedPayload = shescape.escapeAll([payload]);
// And (example)
const result = cp.execSync(`echo Hello ${escapedPayload}`, options);
// 4. Impact
console.log(result.toString());
// Outputs "Hello" followed by the contents of the PATH environment variableFor Shescape prior to v2.0.0, the options object must have shell: 'cmd.exe' or shell: undefined and interpolation: true.
Patches
This bug has been patched in v2.1.2 which you can upgrade to now.
If you are already using v2 of Shescape, no further changes are required. If you are using v1 of Shescape, follow the migration guide to upgrade to v2. There is no plan to release a patch compatible with v1 of Shescape.
Workarounds
Alternatively, users can remove all instances of % from user input before using Shescape.
References
For more information
- Comment on Pull Request #1916
- Comment on commit 0a81f1e
- Open an issue at https://github.com/ericcornelissen/shescape/issues (New issue > Question)
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | shescape | >= 1.7.2, < 2.1.2 | 2.1.2 |
References
- https://github.com/ericcornelissen/shescape/security/advisories/GHSA-66pp-5p9w-q87j
- https://nvd.nist.gov/vuln/detail/CVE-2025-30222
- https://github.com/ericcornelissen/shescape/pull/1916
- https://github.com/ericcornelissen/shescape/commit/0a81f1eb077bab8caae283a2490cd7be9af179c6
- https://github.com/ericcornelissen/shescape
- https://github.com/ericcornelissen/shescape/releases/tag/v2.1.2
- CVSS vector
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U- Weakness (CWE)
CWE-200- Platform
- npm
- Package
shescape- Disclosed
- 26.03.2025
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-66pp-5p9w-q87j - CC BY 4.0
Vulnerability history: shescape
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 13
- First → latest
- 03.2021 07.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 2
- High 5
- Medium 4
- Low 2
Disclosures per year
- 2021: 1
- 2022: 4
- 2023: 2
- 2024: 0
- 2025: 1
- 2026: 5
-
Shescape has potential environment variable exposure on Windows with CMD this entry
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