CVE-2025-30222 — shescape
Fix: ericcornelissen/shescape@0a81f1eCVE-2025-30222 is a Information Exposure vulnerability in shescape. A fix is available for shescape — see the affected versions and patch details below.
Shescape has potential environment variable exposure on Windows with CMD
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-30222.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
shescapenpmDescription
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 variable
For 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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | shescape | ≥ 1.7.2&&< 2.1.2 | 2.1.2npm install shescape@2.1.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for shescape, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update shescape to 2.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-30222 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-30222 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-30222. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-30222 in your dependencies?
O3 Security finds CVE-2025-30222 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.