Security vulnerability information aggregation techniques are disclosed. Vulnerability information associated with one or more security vulnerabilities is obtained from multiple sources and aggregated into respective unified vulnerability definitions for the one or more security vulnerabilities. Aggregation may involve format conversion, content aggregation, or both in some embodiments. Unified vulnerability definitions may be distributed to vulnerability information consumers in accordance with consumer-specific policies. Storage of vulnerability information received from the sources may allow the aggregation process to be performed on existing vulnerability information “retro-actively”. Related data structures and Graphical User Interfaces (GUIs) are also disclosed.