Vendure is an open-source headless commerce platform. Prior to 3.6.5, the public Shop GraphQL API allows an unauthenticated caller to supply a catastrophically backtracking pattern through StringOperators.regex. packages/core/src/service/helpers/list-query-builder/parse-filter-params.ts passes the raw pattern to the REGEXP implementation registered by packages/core/src/service/helpers/list-query-builder/list-query-builder.ts, and better-sqlite3 and sqljs evaluate it synchronously in the Node.js event loop. ShopProductsResolver.products is publicly reachable, so one nested-quantifier pattern can block request processing and make the storefront and admin API unavailable, while repeated requests can sustain denial of service. PostgreSQL and MySQL or MariaDB deployments do not execute this…