In several parts of the world, forests have been safeguarded by Indigenous and traditional people, whose plant food production is mostly for self-consumption and for sale based on the promotion of forest biological processes and crop diversification. In the Brazilian Atlantic Forest, Quilombola groups are black communities that have protected and managed agrobiodiversity since the fifteenth century. Although the dynamics of use, production, and donations of Quilombola food plants are still poorly understood, these processes can help us to understand the vulnerability to food insecurity. We analyzed the food security related to food availability in a Quilombola community in southern Brazil (São Roque Pedra Branca), focusing on their dependence on locally produced food plants. Today, São Roque families depend on agriculture, government benefits, and urban low-paid civil construction and general helper jobs. We evaluated the interactions between Quilombola farmers and the cultivated species and varieties and the role of farmer families within the community. The hypothesis is that farmers who produce, manage, and conserve more local species and varieties of plants also contribute to less food vulnerability within the community. The small-scale agriculture carried out by the Quilombolas implies the management of high inter- and intraspecific diversity. During the 2019 agricultural year, 42 species were cultivated in plots and gardens, comprising 83 varieties. Most farmers cultivate a subset of major species and varieties for self-consumption and donations. The farmers who grow the most varieties are the ones who donate the most. Some vulnerability to food insecurity was observed in 53% of the family units. Exchanges and donations between families contribute to the community's food security, but there are still families in a situation of food insecurity. Local agrobiodiversity and established exchange networks strengthen Quilombola food sovereignty.