Shopware 6 is an open commerce platform based on Symfony Framework and Vue. Starting in version 6.3.5.0 and prior to versions 6.6.1.0 and 6.5.8.8, when a authenticated request is made to POST /store-api/account/logout, the cart will be cleared, but the User wont be logged out. This affects only the direct store-api usage, as the PHP Storefront listens additionally on CustomerLogoutEvent and invalidates the session additionally. The problem has been fixed in Shopware 6.6.1.0 and 6.5.8.8. Those who are unable to update can install the latest version of the Shopware Security Plugin as a workaround.
According to WASC, “Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization.”