Command Injection Affecting composer/composer package, versions >=2.0.0, <2.2.27>=2.3.0, <2.9.6
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PHP-COMPOSERCOMPOSER-16066745
- published15 Apr 2026
- disclosed14 Apr 2026
- creditSaku0512
Introduced: 14 Apr 2026
NewCVE-2026-40176 (opens in a new tab)How to fix?
Upgrade composer/composer to version 2.2.27, 2.9.6 or higher.
Overview
composer/composer is a Dependency Manager for PHP. Composer helps you declare, manage and install dependencies of PHP projects. It ensures you have the right stack everywhere.
Affected versions of this package are vulnerable to Command Injection via the generateP4Command function. An attacker can execute arbitrary commands in the context of the user running the process by supplying malicious Perforce connection parameters in a crafted configuration file. This is only exploitable if Composer commands are run on untrusted projects with attacker-supplied configuration files.
Workaround
This vulnerability can be mitigated by carefully inspecting configuration files before running Composer and ensuring Perforce-related fields contain valid values, and by only running Composer commands on projects from trusted sources.