Stage.js through 0.8.10 allows DOM Clobbering (with resultant XSS for untrusted input that contains HTML but does not directly contain JavaScript), because document.currentScript lookup can be shadowed by attacker-injected HTML elements.
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.