Open-Source Security Intelligence

Know every vulnerability
before it knows you.

DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.

Checkout DevGuardView on GitHub
Search

GHSA-4c96-w8v2-p28j

HighCVSS 8.1 / 10
Published Mar 13, 2026·Last modified Mar 14, 2026
Affected Components(0)

No affected components available

Description

Summary

A command injection vulnerability exists in Deno's node:child_process polyfill (shell: true mode) that bypasses the fix for CVE-2026-27190 (GHSA-hmh4-3xvx-q5hr). An attacker who controls arguments passed to spawnSync or spawn with shell: true can execute arbitrary OS commands, bypassing Deno's permission system.

Affected versions: Deno v2.7.0, v2.7.1

Details

The two-stage argument sanitization in transformDenoShellCommand (ext/node/polyfills/internal/child_process.ts) has a priority bug: when an argument contains a $VAR pattern, it is wrapped in double quotes (L1290) instead of single quotes (L1293). Double quotes in POSIX sh do not suppress backtick command substitution, allowing injected commands to execute.

Attack chain:

  1. escapeShellArg wraps the argument in single quotes (safe)
  2. op_node_parse_shell_args strips the single-quote delimiters during tokenization (raw argument exposed)
  3. Re-quoting detects $VAR pattern → applies double quotes
  4. Backtick payload inside double quotes executes via /bin/sh

Impact

OS Command Injection (CWE-78). Any application using node:child_process spawn/spawnSync with shell: true and user-controlled arguments is vulnerable. Injected commands execute at the OS process level, outside Deno's permission sandbox. Only --allow-run is required.

Mitigation

Avoid passing user-controlled input as arguments to spawn/spawnSync with shell: true. Use shell: false (the default) instead, or validate/sanitize inputs before passing them.

Risk Scores
Base Score
8.1

The vulnerability can be exploited over the network without needing physical access. It is difficult for an attacker to exploit this vulnerability and may require special conditions. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a high impact on the availability of the system.

Threat Intelligence
7.4

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
1.48%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

Browse More

High severity
Scan your project

Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.

Checkout DevGuard