Composer up to 2.2.29/2.10.2 Symlink installed.json symlink

Summaryinfo

A vulnerability has been found in Composer up to 2.2.29/2.10.2 and classified as problematic. The impacted element is an unknown function of the file vendor/composer/installed.json of the component Symlink. Performing a manipulation results in symlink. This vulnerability is reported as CVE-2026-59944. The attack requires a local approach. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic has been found in Composer up to 2.2.29/2.10.2. This affects an unknown part of the file vendor/composer/installed.json of the component Symlink. The manipulation with an unknown input leads to a symlink vulnerability. CWE is classifying the issue as CWE-61. The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-59944 since 07/07/2026. The exploitability is told to be easy. An attack has to be approached locally. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

By approaching the search of inurl:vendor/composer/installed.json it is possible to find vulnerable targets with Google Hacking.

Upgrading to version 2.2.30 or 2.10.3 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• Composer

Version

• 2.2.0
• 2.2.1
• 2.2.2
• 2.2.3
• 2.2.4
• 2.2.5
• 2.2.6
• 2.2.7
• 2.2.8
• 2.2.9
• 2.2.10
• 2.2.11
• 2.2.12
• 2.2.13
• 2.2.14
• 2.2.15
• 2.2.16
• 2.2.17
• 2.2.18
• 2.2.19
• 2.2.20
• 2.2.21
• 2.2.22
• 2.2.23
• 2.2.24
• 2.2.25
• 2.2.26
• 2.2.27
• 2.2.28
• 2.2.29
• 2.10.0
• 2.10.1
• 2.10.2

Website

• Product: https://github.com/composer/composer/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion