7.0
HIGH CVSS 3.1
CVE-2026-59948
Composer: Arbitrary file write outside vendor via malicious transitive package name
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.

INFO

Published Date :

July 8, 2026, 8:16 p.m.

Last Modified :

July 8, 2026, 8:16 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-59948 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH [email protected]
Solution
Update Composer to a fixed version to prevent arbitrary file writes.
  • Update Composer to version 2.2.29 or later.
  • Update Composer to version 2.10.2 or later.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-59948 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-59948 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-59948 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 08, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'composer', 'product': 'composer', 'versions': [{'status': 'affected', 'version': '>= 1.0, < 2.2.29'}, {'status': 'affected', 'version': '>= 2.3.0, < 2.10.2'}]}]
    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.
    Added CVSS V3.1 AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
    Added CWE CWE-22
    Added CWE CWE-787
    Added Reference https://github.com/composer/composer/commit/502c6c4f699802d9cf464728b3e8a95674f919a0
    Added Reference https://github.com/composer/composer/commit/c50b1efd13ebd73f6dca19b31424c5a02bf93cc1
    Added Reference https://github.com/composer/composer/releases/tag/2.10.2
    Added Reference https://github.com/composer/composer/releases/tag/2.2.29
    Added Reference https://github.com/composer/composer/security/advisories/GHSA-499r-g7pc-vmp9
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.