This study aims to examine the effect of fintech adoption on the financial vulnerability of Iranian households, with an emphasis on the mediating role of financial inclusion and the moderating role of financial literacy. Despite the rapid expansion of digital financial services in Iran, there is limited empirical evidence on whether this expansion actually leads to a reduction in households' financial vulnerability, particularly in an economy marked by chronic inflation and sanctions-related constraints. The research data were collected through a structured online questionnaire from 364 Iranian households using digital financial services, and were analyzed using partial least squares structural equation modeling (PLS-SEM) in SmartPLS software. The results showed that fintech adoption has a significant positive effect on financial inclusion, and financial inclusion in turn has a significant negative effect on household financial vulnerability. In addition, fintech adoption directly reduces household financial vulnerability, and financial inclusion partially mediates this relationship. Furthermore, financial literacy, as a moderating variable, strengthens the mitigating effect of fintech on financial vulnerability among households with higher financial literacy. The findings suggest that policymakers and financial institutions should pursue the development of fintech infrastructure alongside the genuine expansion of financial inclusion and the enhancement of households' financial literacy, in order to strengthen household-level financial resilience against economic shocks.