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, UrlGenerator validates route parameters against a pattern built as ^ plus the raw requirement plus $; with ungrouped alternations, middle alternatives match as unanchored substrings, allowing a value such as //evil.com to satisfy a common locale requirement and generate a protocol-relative off-site URL. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.
https://github.com/symfony/symfony/security/advisories/GHSA-72xp-p242-47p9
https://github.com/symfony/symfony/releases/tag/v8.0.12
https://github.com/symfony/symfony/releases/tag/v7.4.12
Published: 2026-07-14
Updated: 2026-07-14
Base Score: 7.5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P
Severity: High
Base Score: 9.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
Base Score: 2.3
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Severity: Low
EPSS: 0.0004