CVE-2026-59948

Composer: Arbitrary file write outside vendor via malicious transitive package name

Published Jul 8, 2026 CVSS 3.1 · 7 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-499r-g7pc-vmp9 Composer: Arbitrary file write outside vendor via malicious transitive package name
History
Type Values Removed Values Added
First Time appeared Getcomposer
Getcomposer composer
Vendors & Products Getcomposer
Getcomposer composer
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title Composer: Arbitrary file write outside vendor via malicious transitive package name
Weaknesses CWE-22
CWE-787
References
Metrics cvssV3_1

{'score': 7, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 9, 2026, 2:32 PM
Reserved
Jul 7, 2026, 6:49 PM
Status
Deferred
Published
Jul 8, 2026, 8:16 PM
Modified
Jul 10, 2026, 7:14 PM