CVE-2026-45305: Sensiolabs Symfony

High severity, CVSS 7.5. EPSS: 0.7% chance of exploitation in the next 30 days.

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, Symfony\Component\Yaml\Parser::cleanup() used regular expressions with overlapping quantifiers for YAML directive, comment, and document marker cleanup, allowing crafted input to make parsing hang for an arbitrarily long time. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

Affected products

• Sensiolabs Symfony: before 5.4.52 (fixed in 5.4.52); from 6.0.0, before 6.4.40 (fixed in 6.4.40); from 7.0.0, before 7.4.12 (fixed in 7.4.12); from 8.0.0, before 8.0.12 (fixed in 8.0.12)

Published 2026-07-14. Last modified 2026-07-15.