How severe is GHSA-w4hw-qcx7-56pr?

No CVSS score has been assigned to GHSA-w4hw-qcx7-56pr yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-w4hw-qcx7-56pr?

GHSA-w4hw-qcx7-56pr affects the following packages: shescape (npm), shescape (npm). Ecosystems affected: npm.

How do I fix GHSA-w4hw-qcx7-56pr?

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.

How do I detect GHSA-w4hw-qcx7-56pr in my npm dependencies?

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.

How do I mitigate GHSA-w4hw-qcx7-56pr if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is GHSA-w4hw-qcx7-56pr actively exploited in the wild?

No public exploit code has been indexed for GHSA-w4hw-qcx7-56pr yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-w4hw-qcx7-56pr?

GHSA-w4hw-qcx7-56pr has an EPSS (Exploit Prediction Scoring System) score of 0.9%, placing it in the 58th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-w4hw-qcx7-56pr?

GHSA-w4hw-qcx7-56pr is classified as OS Command Injection (CWE-78), CWE-150 (CWE-150). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-w4hw-qcx7-56pr published, and has it been updated?

GHSA-w4hw-qcx7-56pr was published on July 24, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

GHSA-w4hw-qcx7-56pr — shescape

Fix: ericcornelissen/shescape#2649

GHSA-w4hw-qcx7-56pr is a OS Command Injection vulnerability in shescape. A fix is available for shescape — see the affected versions and patch details below.

Shescape: Shell injection via unescaped parentheses on Windows with CMD

Also known asCVE-2026-73414

Published

Jul 24, 2026

Updated

Aug 12, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Sep 26, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs58th percentile — riskier than 58% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

2 pkgs affected

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.

25other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

shescapenpm

23Kdownloads / 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

Comment on Pull Request [#2651] for v2 and [#2649] for v3
Comment on commit [b4b34c3] for v2 and [43d70b5] for v3
Open an issue at https://github.com/ericcornelissen/shescape/issues (New issue > Question)

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`shescape`	all versions	2.1.14`npm install shescape@2.1.14`
📦npm	`shescape`	≥ 3.0.0&&< 3.0.1	3.0.1`npm install shescape@3.0.1`

Detection & mitigation playbook

Open-source dependency

Detect
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 2.1.14 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.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

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

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