CVE-2026-59948
Composer: Arbitrary file write outside vendor via malicious transitive package name
CVSS Score
7.0
EPSS Score
0.1%
EPSS Percentile
3th
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.
| CWE | CWE-22 CWE-787 |
| Vendor | composer |
| Product | composer |
| Published | Jul 8, 2026 |
| Last Updated | Jul 9, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H Attack Vector
Local
Attack Complexity
High
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
composer / composer
>= 1.0, < 2.2.29 >= 2.3.0, < 2.10.2
References
github.com: https://github.com/composer/composer/security/advisories/GHSA-499r-g7pc-vmp9 github.com: https://github.com/composer/composer/commit/502c6c4f699802d9cf464728b3e8a95674f919a0 github.com: https://github.com/composer/composer/commit/c50b1efd13ebd73f6dca19b31424c5a02bf93cc1 github.com: https://github.com/composer/composer/releases/tag/2.10.2 github.com: https://github.com/composer/composer/releases/tag/2.2.29