high8.1
CVE-2026-40880
Zebra: Cached Mempool Verification Bypasses Consensus Rules for Ahead-of-Tip Blocks
Impact
ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.3.1 and zebra-consensus version 5.0.2, a logic error in Zebra's transaction verification cache could allow a malicious miner to induce a consensus split. By carefully submitting a transaction that is valid for height H+1 but invalid for H+2 and then mining that transaction in a block at height H+2, a miner could cause vulnerable Zebra nodes to accept an invalid block, leading to a consensus split from the rest of the Zcash network. This vulnerability is fixed in zebrad version 4.3.1 and zebra-consensus version 5.0.2.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rust | zebra-consensus | < 5.0.2 | 5.0.2 |
| rust | zebrad | < 4.3.1 | 4.3.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Zfnd | Zebra-Consensus | before 5.0.2 |
| Zfnd | Zebrad | before 4.3.1 |