CVE-2026-59948
Composer: Arbitrary file write outside vendor via malicious transitive package name
7.0
HIGH
CVSS 3.1
EPSS 0.13%
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.
How to fix CVE-2026-59948
To remediate CVE-2026-59948, upgrade the affected package to a fixed version below.
- —upgrade to 2.10.2 or later
Is CVE-2026-59948 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 2.3.0, < 2.10.2
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.0 | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H |