GHSA-q53c-4prm-w95q
Shescape: Home-directory disclosure in assignment context on Unix with Dash
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
shescapenpmDescription
Impact
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
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 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.
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)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | shescape | all versions | 2.1.14 |
| 📦npm | shescape | ≥ 3.0.0&&< 3.0.1 | 3.0.1 |
Detection & mitigation playbook
Open-source dependencyDetect
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.
Fix
Update shescape to 2.1.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q53c-4prm-w95q 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 pinpoints whether GHSA-q53c-4prm-w95q 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-q53c-4prm-w95q. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-q53c-4prm-w95q in your dependencies?
O3 detects GHSA-q53c-4prm-w95q across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.