Composer up to 2.2.28/2.10.1 Binary Installation Flow information disclosure

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Composer up to 2.2.28/2.10.1. This issue affects some unknown processing of the component Binary Installation Flow. Performing a manipulation results in information disclosure. This vulnerability is reported as CVE-2026-59946. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Composer up to 2.2.28/2.10.1. It has been classified as problematic. This affects an unknown functionality of the component Binary Installation Flow. The manipulation with an unknown input leads to a information disclosure vulnerability. CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality. The summary by CVE is:

Composer is a dependency Manager for the PHP language. Prior to 2.2.29 and 2.10.2, a Composer package bin entry containing .. path segments can resolve outside the package install directory and cause Composer's binary installation flow to chmod an existing host file to a world-readable and world-executable mode during composer install, update, or require. This issue is fixed in versions 2.2.29 and 2.10.2.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-59946 since 07/07/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

Upgrading to version 2.2.29 or 2.10.2 eliminates this vulnerability.

Be aware that VulDB is the high quality source for 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
• 2.10.0
• 2.10.1

Website

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

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Be aware that VulDB is the high quality source for vulnerability data.

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