Composer Remote Code Execution vulnerability via web-accessible composer.phar
Impact
Users publishing a composer.phar to a public web-accessible server where the composer.phar can be executed as a php file may be impacted if PHP also has register_argc_argv enabled in php.ini.
Patches
2.6.4, 2.2.22 and 1.10.27 patch this vulnerability.
Workarounds
Make sure register_argc_argv is disabled in php.ini, and avoid publishing composer.phar to the web as this really should not happen.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | composer/composer | < 1.10.27, >= 2.0.0, < 2.2.22, >= 2.3.0, < 2.6.4 | 1.10.27, 2.2.22, 2.6.4 |
References
- https://github.com/composer/composer/security/advisories/GHSA-jm6m-4632-36hf
- https://nvd.nist.gov/vuln/detail/CVE-2023-43655
- https://github.com/composer/composer/commit/4fce14795aba98e40b6c4f5047305aba17a6120d
- https://github.com/composer/composer/commit/955a48e6319c8962e5cd421b07c00ab3c728968c
- https://github.com/composer/composer/commit/95e091c921037b7b6564942845e7b738f6b95c9c
- https://github.com/composer/composer
- https://lists.debian.org/debian-lts-announce/2024/03/msg00030.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/66H2WKFUO255T3BZTL72TNYJYH2XM5FG
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/7AWYAUZNH565NWPIKGEIYBWHYNM5JGAE
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KFOPGPW2KS37O3KJWBRGTUWHTXCQXBS2
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H- Weakness (CWE)
CWE-74- Platform
- Composer
- Package
composer/composer- Disclosed
- 29.09.2023
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-jm6m-4632-36hf - CC BY 4.0
Vulnerability history: composer/composer
All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 17
- First → latest
- 04.2021 10.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 13
- Medium 3
- Low 1
Disclosures per year
- 2021: 2
- 2022: 1
- 2023: 2
- 2024: 3
- 2025: 1
- 2026: 8
-
Composer Remote Code Execution vulnerability via web-accessible composer.phar this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.