Chartbrew is an open-source web application that can connect directly to databases and APIs and use the data to create charts. Prior to 5.2.3, a date-typed MongoDB variable placed inside a quoted query placeholder was inserted as an unescaped string, unlike the safely escaped or coerced string, number, and Boolean branches. The vulnerable surface is mongoDB-backed public, shareable, or embedded charts processed by date-variable substitution. An unauthenticated user supplies a crafted URL filter to a public, shareable, or embedded MongoDB chart whose query places a date-typed variable in a quoted literal. The crafted date value breaks out of the quoted literal and changes query logic; the cha