# CVE-2026-49402: Deno OS command injection in node:child_process on Windows

Source: https://junglewise.ai/threats/cve-2026-49402-deno-os-command-injection-in-node-child-process-on-windows  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-23. Updated: 2026-06-23  
License: CC BY 4.0 with a link back

CVE-2026-49402 · Severity: high · CVSS 8.1 · Published 2026-06-23

Deno is a runtime environment used to run JavaScript and TypeScript applications. A security flaw in how Deno handles external commands on Windows allows attackers to inject and execute their own malicious commands. This could lead to a full system takeover or unauthorized data access if an application processes untrusted user input through certain system functions.

Technologies: [deno (crates.io)](https://junglewise.ai/threats/technologies/deno). Vendors: [crates.io](https://junglewise.ai/threats/vendors/crates-io).

## Quick answers

**Is CVE-2026-49402 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-49402 being exploited in the wild.

**How severe is CVE-2026-49402?** High severity, with a CVSS score of 8.1, published 23 June 2026.

**Which products and versions are affected?** deno (crates.io) < 2.7.10, SEMVER:introduced=0,fixed=2.7.10.

**Is there a fix for CVE-2026-49402?** Yes. deno (crates.io): upgrade to 2.7.10 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-49402 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-49402?** Check whether you run deno (crates.io) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- deno (crates.io): upgrade to 2.7.10 or later

  ```sh
  cargo update -p deno
  ```


## Technical details

An OS command injection vulnerability exists in Deno's node:child_process implementation on Windows due to insufficient sanitization in the escapeShellArg() helper. When functions like spawn, spawnSync, or exec are called with shell: true, the helper fails to quote arguments containing cmd.exe metacharacters (such as &, |, <, >, ^, !, (, and )) and does not neutralize the % character used for environment variable expansion. An attacker who can control any portion of an argument passed to these functions can inject arbitrary commands or leak environment variables. This issue is specific to Windows and was resolved in Deno version 2.7.10.

## Affected products

- denoland Deno < 2.7.10

## Identifiers

- CVE-2026-49402
- GHSA-7xh3-mhg9-jcw8

## Timeline

- 2026-05-27: advisory: GitHub advisory published by denoland
- 2026-06-23: disclosed: NVD publication date
- 2026-06-23: patched: Fix confirmed in version 2.7.10

## References

- [https://github.com/denoland/deno/security/advisories/GHSA-7xh3-mhg9-jcw8](https://github.com/denoland/deno/security/advisories/GHSA-7xh3-mhg9-jcw8)

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- [Deno environment permission bypass in process.loadEnvFile](https://junglewise.ai/threats/cve-2026-49983-deno-environment-permission-bypass-in-process-loadenvfile)
- [Deno sandbox bypass via missing post-DNS check in WebSocket API](https://junglewise.ai/threats/cve-2026-49860-deno-sandbox-bypass-via-missing-post-dns-check-in-websocket-api)
- [Deno network restriction bypass in fetch API](https://junglewise.ai/threats/cve-2026-49859-deno-network-restriction-bypass-in-fetch-api)
- [Deno missing cryptographic rounds in node:crypto checkPrime](https://junglewise.ai/threats/cve-2026-49440-deno-missing-cryptographic-rounds-in-node-crypto-checkprime)