Composer up to 2.2.29/2.10.2 Perforce Composer\Util\Perforce source.url os command injection

Summaryinfo

A vulnerability classified as critical was found in Composer up to 2.2.29/2.10.2. Impacted is the function Composer\Util\Perforce of the component Perforce. The manipulation of the argument source.url results in os command injection. This vulnerability was named CVE-2026-84361. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as critical has been found in Composer up to 2.2.29/2.10.2. Affected is the function Composer\Util\Perforce of the component Perforce. The manipulation of the argument source.url with an unknown input leads to a os command injection vulnerability. CWE is classifying the issue as CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Composer is a dependency Manager for the PHP language. From 1.0 until 2.2.30 and 2.10.3, a malicious dependency package from a custom Composer repository or an untrusted composer.lock file could set source.type to perforce and source.url to an rsh: or jsh: P4PORT value. When the Perforce p4 client was installed and Composer installed the package from source through composer install or composer update, including --prefer-source, Composer\Util\Perforce passed the address to p4 without validation, causing p4 to run a local command with the privileges of the user or CI account. Packagist.org does not permit Perforce source metadata. This issue is fixed in versions 2.2.30 and 2.10.3.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-84361 since 09/01/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1202.

The vulnerability scanner Nessus provides a plugin with the ID 342504 (Linux Distros Unpatched Vulnerability : CVE-2026-84361), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.2.30 or 2.10.3 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (342504). Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

• Composer

Version

• 2.2.0
• 2.2.1
• 2.2.2
• 2.2.3
• 2.2.4
• 2.2.5
• 2.2.6
• 2.2.7
• 2.2.8
• 2.2.9
• 2.2.10
• 2.2.11
• 2.2.12
• 2.2.13
• 2.2.14
• 2.2.15
• 2.2.16
• 2.2.17
• 2.2.18
• 2.2.19
• 2.2.20
• 2.2.21
• 2.2.22
• 2.2.23
• 2.2.24
• 2.2.25
• 2.2.26
• 2.2.27
• 2.2.28
• 2.2.29
• 2.10.0
• 2.10.1
• 2.10.2

Website

• Product: https://github.com/composer/composer/

CPE 2.3info

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CPE 2.2info

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Once again VulDB remains the best source for vulnerability data.

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