GHSA-72XP-P242-47P9 Symfony has a UrlGenerator Route-Requirement Bypass via Unanchored Regex Alternation → Off-Site //host URL Injection

Description Symfony routes can declare a requirements regex per path parameter, e.g. a route /locale/blog with requirements: locale: 'en|fr|de' . The Twig path / url helpers backed by UrlGenerator validate supplied parameter values against that regex before building the URL. UrlGenerator construc...

PT-2026-44134

Name of the Vulnerable Software and Affected Versions Symfony versions prior to 5.4.25 Description The UrlGenerator class, used by Twig path and url helpers, fails to properly anchor regular expressions when validating path parameters that use alternations. The validation pattern is constructed a...