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GHSA-w4hw-qcx7-56pr

Shescape: Shell injection via unescaped parentheses on Windows with CMD

Published
Jul 24, 2026
Updated
Jul 24, 2026
Affected
2 pkgs
Patched
2 / 2
Exploits
None indexed

Blast Radius

2 pkgs affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

shescapenpm
14Kdownloads / week

Description

Impact

This impacts users of Shescape on Windows that explicitly configure shell to CMD, or true with the default shell being CMD, using the escape and escapeAll APIs.

An attacker may be able to achieve shell injection depending on the original command.

import * as cp from "node:child_process";
import { Shescape } from "shescape";

// 1. Prerequisites
const options = {
    shell: "cmd.exe",
    // Or
    shell: true, // Only if the default shell is CMD
};

// 2. Payload
const payload = "x) else if a==a (echo y";

// 3. Usage
const shescape = new Shescape(options);
let escapedPayload;

escapedPayload = shescape.escape(payload);
// Or
escapedPayload = shescape.escapeAll([payload]);

// And (example)
const result = cp.execSync(`if defined FALSY (echo ${escapedPayload})`, options);

// 4. Impact
console.log(result.toString());
// Outputs "y" instead of ""

Patches

This bug has been patched in [v2.1.14] and [v3.0.1] which you can upgrade to now.

If you are already using v3 of Shescape, no further changes are required. If you are using v2 of Shescape is recommended to upgrade as this version reaches end-of-life status on 2026-09-28, follow the [migration guide] to upgrade to v3.

No patches will be released for version of Shescape lower than v2.0.0.

Workarounds

Alternatively, users of Shescape can remove all instances of ( and ) from untrusted inputs.

For more information

Affected Packages

2 total 2 fixed
EcosystemPackageVulnerable rangeFix
📦npmshescapeall versions2.1.14
📦npmshescape≥ 3.0.0&&< 3.0.13.0.1

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for shescape. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update shescape to 2.1.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w4hw-qcx7-56pr is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 pinpoints whether GHSA-w4hw-qcx7-56pr is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-w4hw-qcx7-56pr. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact This impacts users of Shescape on Windows that explicitly configure `shell` to CMD, or `true` with the default shell being CMD, using the `escape` and `escapeAll` APIs. An attacker may be able to achieve shell injection depending on the original command. ```javascript import * as cp from "node:child_process"; import { Shescape } from "shescape"; // 1. Prerequisites const options = { shell: "cmd.exe", // Or shell: true, // Only if the default shell is CMD }; // 2. Payload const payload = "x) else if a==a (echo y"; // 3. Usage const shescape = new Shescape(options);
O3 Security · Impact-Aware SCA

Is GHSA-w4hw-qcx7-56pr in your dependencies?

O3 detects GHSA-w4hw-qcx7-56pr across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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