# Solana — CWE-407 Scan Result: CLEAN

**Scanned:** `runtime/src/bank.rs`, `runtime/src/bank_forks.rs`,
`core/src/banking_stage/`, `core/src/consensus.rs`,
`runtime/src/non_circulating_supply.rs`

## Findings

All `contains()` calls on hot paths use proper O(1) data structures:

| File | Collection | Type | Verdict |
|------|-----------|------|---------|
| `bank.rs:358` | `mentioned_addresses` | `HashSet<Pubkey>` | CLEAN |
| `bank.rs:5379` | `rent_paying_pubkeys` | `HashSet<Pubkey>` | CLEAN |
| `bank.rs:7335` | `new_feature_activations` | `HashSet<Pubkey>` | CLEAN |
| `bank_forks.rs:67` | `descendants` | `HashMap<Slot, HashSet<Slot>>` | CLEAN |
| `banking_stage/read_write_account_set.rs` | `read_set`, `write_set` | `HashSet<Pubkey>` | CLEAN |
| `consensus.rs:922` | `locked_out_vote_accounts` | `HashSet` | CLEAN |
| `consensus.rs:883` | `last_vote_ancestors` | `HashSet<Slot>` | CLEAN |
| `non_circulating_supply.rs:56` | `withdraw_authority_list` | `&[Pubkey]` (10 entries, cold path) | CLEAN |

The `non_circulating_supply.rs` uses `&[Pubkey].contains()` on a static list
of 10 entries. This is called only on RPC queries for supply calculation, not
on the transaction hot path. Bounded and cold — not a defect.

`consensus.rs` `descendants.iter().any()` iterates a `HashSet<u64>` (descendant
slots per fork). The outer loop is bounded by active fork count, and the inner
`HashSet` `.any()` is O(D) but D is small and the structure is unavoidably
linear — no algorithmic improvement possible without restructuring fork tracking.
Not a CWE-407 defect.

## Conclusion

Solana's banking and consensus hot paths are already using hash-based membership
structures throughout. No CWE-407 defects found.
