---
id: CVE-2026-84361
title: Composer is a dependency Manager for the PHP language
summary: >-
  Composer is a dependency Manager for the PHP language. From 1.0 until 2.2.30
  and 2.10.3, a malicious dependency package from a custom Composer repository
  or an untrusted composer.lock file could set source.type to perforce and
  source.url…
severity: high
cwe:
  - CWE-78
vendor: composer
product: composer/composer
affected:
  - 'composer/composer >= 2.3.0, < 2.10.3'
  - 'composer/composer >= 1.0, < 2.2.30'
patched:
  - composer/composer 2.10.3
  - composer/composer 2.2.30
published: '2026-09-01'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:09:13.080'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84361'
references:
  - url: >-
      https://github.com/composer/composer/commit/0aac50528e83ed635cf788333635897469440220
    label: security-advisories@github.com
  - url: >-
      https://github.com/composer/composer/commit/199ad81a9cc6a2a5164ad79a8da26b2e19e521af
    label: security-advisories@github.com
  - url: 'https://github.com/composer/composer/releases/tag/2.10.3'
    label: security-advisories@github.com
  - url: 'https://github.com/composer/composer/releases/tag/2.2.30'
    label: security-advisories@github.com
  - url: >-
      https://github.com/composer/composer/security/advisories/GHSA-rvx4-ffvw-m9q3
    label: security-advisories@github.com
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84361'
  - url: 'https://github.com/advisories/GHSA-rvx4-ffvw-m9q3'
tags:
  - nvd
  - exploit-available
  - ghsa
  - composer
epss: 0.00547
epssPercentile: 0.43401
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/Saku0512/CVE-2026-84361-poc'
  checkedAt: '2026-09-25T08:21:17.654Z'
exploitAvailable: true
aliases:
  - GHSA-rvx4-ffvw-m9q3
ecosystem: composer
ingestedAt: '2026-09-08T22:12:30.968Z'
---

## Overview

Composer is a dependency Manager for the PHP language. From 1.0 until 2.2.30 and 2.10.3, a malicious dependency package from a custom Composer repository or an untrusted composer.lock file could set source.type to perforce and source.url to an rsh: or jsh: P4PORT value. When the Perforce p4 client was installed and Composer installed the package from source through composer install or composer update, including --prefer-source, Composer\Util\Perforce passed the address to p4 without validation, causing p4 to run a local command with the privileges of the user or CI account. Packagist.org does not permit Perforce source metadata. This issue is fixed in versions 2.2.30 and 2.10.3.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-84361)

Affected packages:

- `composer/composer >= 2.3.0, < 2.10.3`
- `composer/composer >= 1.0, < 2.2.30`

Patched in:

- `composer/composer 2.10.3`
- `composer/composer 2.2.30`

Source: https://github.com/advisories/GHSA-rvx4-ffvw-m9q3