Supplier concentration is a market pattern in which a relatively small number of vendors hold a large share of contracts or provide essential services. In cyber security, it matters because many organizations may depend on the same products, support teams, update channels, or technical integrations.
Concentration can make procurement and oversight more consistent, but it can also create shared dependencies. A vulnerability, service disruption, or compromised vendor could affect multiple customers, while limited alternatives may make it harder to switch providers. Defenders can assess this risk by mapping critical suppliers and their dependencies, requiring strong security and incident-reporting terms, reviewing access and update controls, and planning alternatives or recovery measures for essential services.