The two-volume set LNCS 15529 and 15530 constitutes the proceedings of the 26th International Conference on Verification, Model Checking, and Abstract Interpretation, VMCAI 2025, held in Denver, CO, USA, during January 20–21, 2025.The 20 full papers together with 2 accepted tool papers and 18 full length regular and case-study papers presented in the proceedings were carefully reviewed and selected from 48 submissions. The program of VMCAI 2025 conference in the core areas of VMCAI including abstract interpretation, programming languages, hardware and software model checking, cyber-physical systems, formal synthesis, formal methods in artificial intelligence, concurrency and other areas.