CVE-2026-59948: Composer

High severity, CVSS 7.0. EPSS: 0.2% chance of exploitation in the next 30 days.

Composer is a dependency Manager for the PHP language. Prior to 2.2.29 and 2.10.2, a maliciously crafted package from an untrusted repository other than Packagist.org or Private Packagist can cause Composer to write attacker-controlled files outside the vendor directory and outside the project during install or update by using an invalid package name that is not correctly validated before dependency-resolution results are written or installed. This issue is fixed in versions 2.2.29 and 2.10.2.

Affected products

• Composer Composer: from 1.0, before 2.2.29 (fixed in 2.2.29); from 2.3.0, before 2.10.2 (fixed in 2.10.2)

Published 2026-07-08. Last modified 2026-07-10.