CVE-2026-45305
High
Description
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.
SeverityHigh
CVSS7.5
Exploit probability—
Product
Sensiolabs Symfony
PublishedJul 14, 2026
First seenJul 14, 2026
Weakness typeCWE-1333CWE-1333
How to fix
Update
- sensiolabs symfony5.4.52, 6.4.40, 7.4.12, 8.0.12 or later
- symfony/yaml5.4.52, 6.4.40, 7.4.12, 8.0.12 or later
- symfony/symfony5.4.52, 6.4.40, 7.4.12, 8.0.12 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| sensiolabs symfony | v < 5.4.52, 6.0.0 ≤ v < 6.4.40, 7.0.0 ≤ v < 7.4.12, 8.0.0 ≤ v < 8.0.12 | 5.4.52, 6.4.40, 7.4.12, 8.0.12 |
| symfony/yamlPackagist | v < 5.4.52, 6.0.0 ≤ v < 6.4.40, 7.0.0 ≤ v < 7.4.12, 8.0.0 ≤ v < 8.0.12 | 5.4.52, 6.4.40, 7.4.12, 8.0.12 |
| symfony/symfonyPackagist | v < 5.4.52, 6.0.0 ≤ v < 6.4.40, 7.0.0 ≤ v < 7.4.12, 8.0.0 ≤ v < 8.0.12 | 5.4.52, 6.4.40, 7.4.12, 8.0.12 |
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