Review reviewHigh

CVE-2026-59948

composer

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.

CVSS: 7
EPSS: 0.13%
CISA KEV: Not listed
Published: 2026.07.09

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.13%

Technical severityCVSS 7

Vulnerability overview

Affected product and versions

Product: composer
Affected versions: >= 1.0, < 2.2.29, >= 2.3.0, < 2.10.2
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that composer and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE: CWE-22, CWE-787