xdg-desktop-portal-hyprland (aka an XDG Desktop Portal backend for Hyprland) before 1.3.3 allows OS command execution, e.g., because single quotes are not used when sending a list of app IDs and titles via the environment.
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.