composer/composer
HighComposerCVE-2026-84361
What to do
Update composer/composer to 2.10.3 or later.
composer require composer/composer:^2.10.3
A remote code execution flaw affects the Composer package composer/composer. Affected versions: >= 2.3.0, < 2.10.3. Fixed from version 2.10.3.
What the flaw allows: An attacker can make the service run their own code.
- Package
- composer/composer
- Ecosystem
- Composer (PHP)
- Class
- Remote code execution
- Affected versions
- >= 2.3.0, < 2.10.3
- Published on
- September 8, 2026
Sources
Entry built automatically from the cited security advisory, with no model rewriting. Acknowledged by the organisation or vendor, notified to an authority, or established by two independent sources.