The 12th edition of the Competition on Software Verification (SV-COMP 2023) is again the largest overview of tools for software verification, evaluating 52 verification systems from 34 teams from 10 countries. Besides providing an overview of the state of the art in automatic software verification, the goal of the competition is to establish standards, provide a platform for exchange to developers of such tools, educate PhD students on reproducibility approaches and benchmarking, and provide computing resources to developers that do not have access to compute clusters. The competition consisted of 23 805 verification tasks for C programs and 586 verification tasks for Java programs. The specifications include reachability, memory safety, overflows, and termination. This year, the competition introduced a new competition track on witness validation, where validators for verification witnesses are evaluated with respect to their quality.