GHSA-Q53C-4PRM-W95Q

Shescape: Home-directory disclosure in assignment context on Unix with Dash

Workarounds

Alternatively, users of Shescape can 1) refrain from using Dash, 2) use the env option of the node:child_process API to inject variables with untrusted values instead, or 3) remove all instances of ~ 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)

This impacts users of Shescape on Unix systems that explicitly configure shell to Dash, or true when the default shell is Dash, using the escape and escapeAll APIs in assignments prefixed to a command.

An attacker may be able to obtain the location of the home directory and, depending on how it is used, change the location on which a command operates in unexpected ways.

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

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

// 2. Payload
const payload = ":~";

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

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

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

// 4. Impact
console.log(result.toString());
// Outputs ":" followed by the user's home directory

Kodem intelligence

Already deployed Kodem?

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 it 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.

1. What is GHSA-Q53C-4PRM-W95Q? GHSA-Q53C-4PRM-W95Q is a medium-severity security vulnerability in shescape (npm), affecting versions < 2.1.14. It is fixed in 2.1.14, 3.0.1.
2. Which versions of shescape are affected by GHSA-Q53C-4PRM-W95Q? shescape (npm) versions < 2.1.14 is affected.
3. Is there a fix for GHSA-Q53C-4PRM-W95Q? Yes. GHSA-Q53C-4PRM-W95Q is fixed in 2.1.14, 3.0.1. Upgrade to this version or later.
4. Is GHSA-Q53C-4PRM-W95Q exploitable, and should I be worried? Whether GHSA-Q53C-4PRM-W95Q is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether GHSA-Q53C-4PRM-W95Q is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix GHSA-Q53C-4PRM-W95Q?
   • Upgrade shescape to 2.1.14 or later
   • Upgrade shescape to 3.0.1 or later

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