---
id: CVE-2026-59944
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 from 2.3.0 until 2.10.3, a malicious or compromised dependency can bypass
  the earlier CVE-2026-59946 binary-path hardening because Composer validates
  litera…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N'
cwe:
  - CWE-22
  - CWE-59
vendor: composer
product: composer
affected:
  - 'composer >= 1.0.0, < 2.2.30'
  - 'composer >= 2.3.0, < 2.10.3'
published: '2026-09-16'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T18:17:10.200'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-59944'
references:
  - url: >-
      https://github.com/composer/composer/commit/53b8bb4c24697b2f00a18cf1ef35a10392701b89
    label: security-advisories@github.com
  - url: >-
      https://github.com/composer/composer/commit/ad649fdfdf8ed826d4a34e0e5690c76a0b4833aa
    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-96h3-5x6v-m776
    label: security-advisories@github.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-59944.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-59944'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2535546'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-59944'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-59944'
  - url: 'https://access.redhat.com/errata/RHSA-2026:63151'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-16T17:29:17.703299Z'
ingestedAt: '2026-09-16T16:59:56.613Z'
scores:
  nvd: 6.1
  vendor: 5
epss: 0.00322
epssPercentile: 0.22532
patched:
  - hardened_images
---

## Overview

Composer is a dependency Manager for the PHP language. From 1.0 until 2.2.30 and from 2.3.0 until 2.10.3, a malicious or compromised dependency can bypass the earlier CVE-2026-59946 binary-path hardening because Composer validates literal parent-directory segments only during dependency resolution, while the symlink and installed-metadata paths described by the advisory skip that validation. A package can ship an in-package binary symlink that resolves outside its installation directory, or attacker-influenced vendor/composer/installed.json metadata can provide an escaping binary path during a reinstall or regeneration of missing vendor/bin entries. The installed-metadata path is reachable only when the vendor directory was not populated by the same validated install run, such as when it is restored from an untrusted cache, copied from an earlier build stage, carried over from an older Composer run, or writable by a lower-trust build step. Composer can follow the path, change the external target's permissions to make it world-readable and executable, and create a runnable vendor/bin proxy to that external file. The issue does not directly read or transmit data and does not by itself provide remote code execution. 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.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Hardened Images · no fix planned: Red Hat Hardened Images · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-59944.json)
- **RHSA-2026:63151** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:63151)