The International Conference on Software and Systems Reuse, Product Lines, and Configuration (VARIABILITY 2026) invites high-quality contributions from researchers and practitioners in software engineering, systems engineering, and related disciplines focussing on a broad spectrum of methods, concepts, and tools for variability. VARIABILITY aims to be the premier forum for the exchange of ideas, experiences, and results in all aspects of software and systems variability management, reuse, software configuration, and customization. As software and systems become increasingly configurable, reusable, and adaptable, managing their variability across all lifecycle phases is more critical—and more challenging—than ever.