EasyAdmin is a fast and modern admin generator for Symfony applications. From 4.0.0 until 4.29.16 and 5.5.1, EasyAdmin serves all backend requests through a single dashboard route and, for custom actions (Action::linkToRoute() and MenuItem::linkToRoute()), swaps the executed controller based on the routeName query parameter on the kernel.controller event. The swap happens after Symfony's security firewall has already evaluated accesscontrol against the original dashboard URL, and the routeName value was not validated. As a result, a path-based accesscontrol rule protecting the target route was never evaluated, so a low-privilege backend user who can reach a single EasyAdmin URL and knows a target route's name can execute that route's controller, bypassing the path-based rule. Only path-based protections are bypassed. Routes whose controller enforces its own authorization with #[IsGranted] or denyAccessUnlessGranted() remain protected because those checks are recomputed against the swapped-in controller. This issue is fixed in versions 4.29.16 and 5.5.1.