CVE-2021-21408: Debian Linux

High severity, CVSS 8.8. EPSS: 2.2% chance of exploitation in the next 30 days.

Smarty is a template engine for PHP, facilitating the separation of presentation (HTML/CSS) from application logic. Prior to versions 3.1.43 and 4.0.3, template authors could run restricted static php methods. Users should upgrade to version 3.1.43 or 4.0.3 to receive a patch.

Affected products

• Debian Debian Linux: version 9.0 only; version 10.0 only; version 11.0 only
• Fedoraproject Fedora: version 36 only; version 37 only
• Smarty Smarty: before 3.1.43 (fixed in 3.1.43); from 4.0.0, before 4.0.3 (fixed in 4.0.3)

Published 2022-01-10. Last modified 2026-06-17.