CVE-2026-40880: Zfnd Zebra-Consensus

High severity, CVSS 8.1. EPSS: 0.4% chance of exploitation in the next 30 days.

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 products

• Zfnd Zebra-Consensus: before 5.0.2 (fixed in 5.0.2)
• Zfnd Zebrad: before 4.3.1 (fixed in 4.3.1)

Published 2026-04-21. Last modified 2026-06-17.