CVE-2018-14774: Sensiolabs Symfony

High severity, CVSS 7.2. EPSS: 1.1% chance of exploitation in the next 30 days.

An issue was discovered in HttpKernel in Symfony 2.7.0 through 2.7.48, 2.8.0 through 2.8.43, 3.3.0 through 3.3.17, 3.4.0 through 3.4.13, 4.0.0 through 4.0.13, and 4.1.0 through 4.1.2. When using HttpCache, the values of the X-Forwarded-Host headers are implicitly set as trusted while this should be forbidden, leading to potential host header injection.

Affected products

• Sensiolabs Symfony: from 2.7.0, up to and including 2.7.48; from 2.8.0, up to and including 2.8.43; from 3.3.0, up to and including 3.3.17; from 3.4.0, up to and including 3.4.13; from 4.0.0, up to and including 4.0.13; from 4.1.0, up to and including 4.1.2

Published 2018-08-03. Last modified 2026-06-17.