CVE-2026-40880 — Zebra: Cached Mempool Verification Bypasses Consensus Rules for Ahead-of-Tip Blocks

Description (CNA)

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 (CNA)

Vendor / product	Versions
ZcashFoundation / zebrad	affected < 4.3.1
ZcashFoundation / zebra-consensus	affected < 5.0.2

CWE

CWE-1025

References

https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-xvj8-ph7x-65gf

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.