OXID eShop Community Edition before 6.0.0 RC3 (development), 4.10.x before 4.10.6 (maintenance), and 4.9.x before 4.9.11 (legacy), Enterprise Edition before 6.0.0 RC3 (development), 5.2.x before 5.2.11 (legacy), and 5.3.x before 5.3.6 (maintenance), and Professional Edition before 6.0.0 RC3 (development), 4.9.x before 4.9.11 (legacy) and 4.10.x before 4.10.6 (maintenance) allow remote attackers to crawl specially crafted URLs (aka "forced browsing") in order to overflow the database of the shop and consequently make it stop working. Prerequisite: the shop allows rendering empty categories to the storefront via an admin option.