CVE-2026-45304
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 resolved YAML collection aliases recursively, allowing a small untrusted YAML input to expand into a multi-gigabyte structure and exhaust memory. 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-776CWE-776
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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