EUVD-2026-100979

The authentication middleware of the JTL-Shop administration backend processes the plugin safe mode toggle on the admin logout route before checking whether the requesting user is authenticated. An unauthenticated remote attacker can therefore switch the shop's plugin safe mode on and off, which deactivates all installed plugins and their functionality, such as payment and shipping integrations, resulting in a shop-wide denial of service. The attack requires a single request and can be automated against many installations.