Buffer overflow in Composer
CVE-2026-59948
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 fil…
Vulnerability class: Path Traversal (Directory Traversal)
CVSS v3 metric
CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.
Affected products
- Composer — versions >= 1.0, < 2.2.29, >= 2.3.0, < 2.10.2
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-59948?
- CVE-2026-59948 is a high-severity vulnerability in Composer, classified under Path Traversal. CVSS score: 7.0/10. Published 2026-07-08.
- How severe is CVE-2026-59948?
- High severity. CVSS v3 base score is 7.0 out of 10.