CVE-2026-40880
Zebra: Cached Mempool Verification Bypasses Consensus Rules for Ahead-of-Tip Blocks
- State
- Published
- Severity
- 7.2 High
- Published
- Apr 21, 2026
- Updated
- Apr 21, 2026
- Reserved
- Apr 15, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.2 High | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H | GitHub_M |
Weaknesses
- CWE-1025 Comparison Using Wrong Factors
Affected Products
| Product | Versions |
|---|---|
zebradZcashFoundation |
|
zebra-consensusZcashFoundation |
|
References
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