# CVE-2026-59944: composer: Composer is a dependency Manager for the PHP language

CVE-2026-59944 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-59944, released September 2, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-59944
- Priority: Routine
- CVSS: 6.1 (medium)
- EPSS: 0.0047
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 16, 2026

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | composer Debian 14 | 2.10.3-1 | [DEBIAN-CVE-2026-59944](https://patchblox.com/security/data/fix/linux/debian-cve-2026-59944.md) | Sep 2, 2026 |
| Linux | composer amzn 2023 | 2.10.3-1.amzn2023.0.1 | [ALAS2023-2026-3136](https://patchblox.com/security/data/fix/linux/alas2023-2026-3136.md) | Sep 28, 2026 |
| Linux | php-composer2 opensuse-leap 16.0 | 2.8.9-160000.6.1 | [OPENSUSE-SU-2026:21970-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21970-1.md) | Sep 29, 2026 |
| Linux | php-composer2 sles 15.7 | 2.6.4-150600.3.23.1 | [SUSE-SU-2026:4288-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4288-1.md) | Sep 22, 2026 |
| Linux | php-composer2 sles 16.0 | 2.8.9-160000.6.1 | [SUSE-SU-2026:23943-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23943-1.md) | Sep 29, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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