CVE-2026-40176

Summary

Composer is a dependency manager for PHP. Versions 1.0 through 2.2.26 and 2.3 through 2.9.5 contain a command injection vulnerability in the Perforce::generateP4Command() method, which constructs shell commands by interpolating user-supplied Perforce connection parameters (port, user, client) without proper escaping. An attacker can inject arbitrary commands through these values in a malicious composer.json declaring a Perforce VCS repository, leading to command execution in the context of the user running Composer, even if Perforce is not installed. VCS repositories are only loaded from the root composer.json or the composer config directory, so this cannot be exploited through composer.json files of packages installed as dependencies. Users are at risk if they run Composer commands on untrusted projects with attacker-supplied composer.json files. This issue has been fixed in Composer 2.2.27 (2.2 LTS) and 2.9.6 (mainline).

Affected Software

VendorProductVersion RangeStatus
composercomposer>= 2.3, < 2.9.6affected
composercomposer>= 1.0, < 2.2.27affected

Weaknesses

  • CWE-20: CWE-20: Improper Input Validation
  • CWE-78: CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

composer: command injection via malicious Perforce repository definition

Additional References

References