HAVE: Host Active Verification Engine for Closing the Contextual Reality Gap in Security Digital Twins

arXiv:2606.06968v1 Announce Type: new Abstract: Security Digital Twins (SDTs) provide continuously updated virtual replicas of infrastructure for threat simulation, yet they rely on theoretical CVSS scores to assign lateral-movement probabilities -- creating the Contextual Reality Gap: risk is overestimated where unacknowledged mitigations neutralize exploits, and drastically underestimated where logic flaws bypass all memory-safety defenses. We present the Host Active Verification Engine (HAVE), an SDT extension that deploys a safety-constrained host agent to measure the empirical probability of compromise $\hat{p}$ via maximum-likelihood estimation over snapshot-isolated Bernoulli trials. A Wilson interval-width confidence weight $\alpha_w$ propagates $\hat{p}$ into Monte Carlo simulations via a Bayesian blending rule formally related to the Beta-Binomial posterior. Evaluation across four vulnerability classes, three security tiers, and two production binaries shows HAVE reduces $P_{\text{reach}}$ by 38.2% in false-positive scenarios and increases it by 132.4% in false-negative scenarios, with a net +124.1% correction; post-HAVE estimates vary by only $1.12\times$ across calibration exponents $\kappa$, versus $4.6\times$ for CVSS-only baselines.