published August 19, 2026
ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, a consensus-valid block containing a long chain of transparent self-spends to one address can permanently halt Zebra nodes. In zebra-state/src/service/finalized_state/zebra_db/transparent.rs, the finalized-state writer originally applied every newly created output as a credit before applying any spent-output debit from the same block. That credit-first ordering can make the intermediate per-address balance exceed MAX_MONEY even though the final net balance is valid, causing an expect-based panic under the panic equals abort release profile. Because zcashd accepts the triggering block and Zebra encounters it again after every restart, the halt persists until patched software is deployed; exploitation requires mining the specially constructed block and temporarily committing sufficient ZEC to the self-spend chain. This issue is fixed in version 4.5.0.