Corpus

The evolving collection of test inputs a fuzzer maintains, used as the base for generating new mutations.

A corpus is the set of test inputs that a coverage-guided fuzzer has selected for retention based on coverage contribution. Each input in the corpus covers at least one code path not covered by any other entry, so the corpus collectively represents the fuzzer's current coverage map. As the fuzzer runs, it mutates corpus entries, and any mutation that discovers a new edge is added to the corpus. Over time the corpus grows until the fuzzer can no longer find uncovered edges — at which point it has likely explored all paths reachable with its mutation strategy. Corpus quality is critical: a good seed corpus that exercises common code paths allows the fuzzer to start from a high-coverage baseline and immediately mutate toward uncovered edges rather than building from scratch.